Basics of Presuppositionalism. What is a Presupposition, exactly?

One of the most voiced criticisms of presuppositionalism is that it "assumes what it is trying to prove." In other words, some say, it is a "circular" argument. These seem to stem from the mistaken belief that a presupposition is something that is merely assumed, either a non-proveable assumption, or something akin to an axiom. 

Let's take each of these starting with the "assumption" claim.  

First, presuppositions are not taken to be synonymous with "merely assumed."  As used in presuppositionalism -- as Greg Bahnsen emphasized -- presuppositions are the basic, non-negotiable claims of a worldview. Also, a presupposition is a necessary belief to account for a "state of affairs."  Neither of these carry the notion of "unprovable assumptions."   In fact the characterization as a "necessary belief" carries with it the idea that such a presupposition is necessary because of the impossibility of the contrary, i.e. to deny it proves it by leading to self-contradiction.  That is the essence of proof used in TAG (the "transcendental argument for God").

We note that the charge of circularity used by opponents is a case of special pleading on their part.  They argue as if their worldview is not guilty of the "sin" of circularity.  Yet their argumentation is circular in the most vicious sort of way.  The most glaring example is the belief in the existence of an unproved disembodied universal abstract logic existing someplace in a materialist cosmos (or just as incoherent a platonic "heaven").  As Bahnsen pointed out it is unprovable on the basis of their presuppositions, citing the example: "How could one prove 'modus ponens' without using 'modus ponens'?"  One can't.  In other words, one has "modus ponens" because of "modus ponens"  -- one can't get more tightly circular than that.

To elaborate, here is a more immediate example from linguistics that illustrates the use of presuppositions in the presuppositional approach of Van Til: "Have you stopped beating your wife?" That question presupposes that the person did in fact engage in wife beating. That is the necessary presupposition that renders the question meaningful. This does not mean the presupposition is true or false. Also, note in this case the presupposition is not of the unprovable variety. In fact, the truth of the presupposition is potentially testable by empirical investigation. 

Above I mentioned that some treat a presupposition as an axiom. Unfortunately, that view was espoused by Gordon H. Clark in his version of presuppositionalism.  I agree with Van Til and Greg Bahnsen that Gordon H. Clark's version of presuppositionalism is fatally flawed¹.  His defense of Christian theism had to ultimately rest on the "axiom of Scripture." This essentially reduced Clark's system to fideism. As Bahnsen summarized: "Clark ultimately left Christianity without a rational defense."²      Clark's system leaned heavily to rationalism and deductive proofs when it came to the positive defense of Christianity. He was vehemently opposed to empirical evidence -- deeming it not a path to any knowledge. So much so that he claimed that science has no cognitive content regarding nature.  Only deductivism provided knowledge. These faults are serious, and actually are self destructive of Clark's system.³   One should be aware of the difference between Van Til's and Clark's  versions of presuppositionalism and not confuse the two.

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1 See Chapter 8.5, p.662 in "Van Til's Apologetic" by Greg Bahnsen for the critiques of Gordon H. Clark.^↩
2 p.672 in "Van Til's Apologetic" by Greg Bahnsen.^↩
3  N.B. Clark's writings are not devoid of value. His history of philosophy "Thales to Dewey" is an excellent text that thoroughly dismantles atheistic thought as being contradictory in all of its historical systems.^↩ 

Reasoning by Presupposition: The Bahnsen-Smith Debate

I was perusing the apologetic blogs a few months back when I came across a comment by an atheist who claimed Christians never refer to the Bahnsen-Smith debate (although that interchange was more a moderated conversation than a debate). Well, that claim is not true. To rebut that claim, here is a link to the audio of that debate. A transcript of the audio can be found here. Another post of the dialog can be found here. This dialog is well worth studying to understand Bahnsen's use of the presuppositional apologetic. Apparently, that atheist thought Smith bested Bahnsen in that encounter. Incredible! Such an opinion, as we will see below, betrays superficiality and an unstudied philosophic naivete. Smith,and a caller-in named Max, clearly had no clue as to what hit them. Bahnsen's irenic answers rebutted all of Smith's claims.

One particular point, that has prompted the title of this article, was when Max charged that Bahnsen merely presupposed God.  Of course, it is not the case that we merely do so (as if, the presupposition of Christianity is a fideistic and unargued assumption). Bahnsen's reply that atheists presuppose atheism was priceless.  This is a perennial blind spot of atheists -- they think they are devoid of presuppositions and are staunch advocates of non-circular reasoning. Nothing could be further from the truth.  Atheists, in fact, argue presupposing atheism (consequently, this atheist's charge against Christians commits the fallacy of special pleading, sometimes called "the double standard fallacy"). However, the fact that both sides have presuppositions does not reduce the debate to a stand off. Not all presuppositions are "created equal." The problem for the atheists is that they have a multitude of unintelligible contradictory assumptions and viciously circular arguments, none of which are mutually coherent, and none which they can make good. This fact renders the atheist's presupposition(s) false and destroys his pretense to knowledge of any sort. This fact is evident in the many debates of presuppositionalists with atheists. Some atheists will even admit (on the basis of their assumptions, of course!) there is no certain knowledge or express doubt that knowledge is possible (not realizing the inherent self contradiction in such claims -- since they must know something in order for their language to intelligibly express their doubt. To put it ironically: "Why should anyone listen to someone who believes he doesn't know what he's saying?") On the other hand, the Christian presupposition is intelligible and provides the necessary grounds for knowledge and for the intelligibility of all of human experience. So again, there is no "stand off."

Here are a few more of the high points in the dialog:

• Max claimed reason is "natural!"  Another priceless moment.  Bahnsen pressed the point that abstract entities are not natural.¹  All Max said by way of "rebuttal" was a repeated "Oh boy!"  Bahnsen challenged atheists to live according to their presuppositions -- something they never do.
• Smith assimilated physical causation and logical laws (logical "law of identity" for instance).  Bahnsen succinctly pointed out that such is a major philosophical error.²  For starters, matter does not move according to abstract laws of rational thought (logic) -- matter obeys inviolable physical laws based on the properties of matter. The material universe is completely oblivious to abstract laws of logic. Laws of logic are standards of rational thought -- laws that can be violated by flawed reasoning.  As we have mentioned repeatedly, laws of logic presuppose minds with rational freedom (independent of material causation) and mental causal efficacy -- something totally antithetical to a universe composed solely of matter moving according to chance and causally inviolable physical laws. (In the materialist universe the only causality is, de facto, physical.) To put it another way, laws of logic are necessary and non-contingent; on the other hand, the physical world is contingent and the laws of physics are not necessary. (If they were, empirical science and experiment would be unnecessary.) This is usually stated succinctly by the phrase "logic says nothing about the contingent world." We should also point out that physicists can construct a multitude of consistent theoretical models of the material universe with existing and hypothetical entities, differing mathematical structures, different causal interactions, different values of fundamental constants, and so on. All of which show that the actual physical reality in which we live is not necessitated by logic. To summarize, logic and physics are categorially distinct. Contra Smith, logic cannot be reduced to physics.
• Smith trotted out the tired and fallacious "Euthyphro dilemma" to counter Christian moral claims.  Bahnsen succinctly rebuffed Smith by pointing out that Christian moral claims are rooted in the character of God Himself.  In Christian theism, God is ne plus ultra³. There is no "super-reality" above God; no laws above God.⁴  

In summary, Bahnsen  began the dialog by engaging Smith on the three fundamental areas of philosophy: (1) What exists? What is real? What are the constituents of reality? (Metaphysics/ontology); (2) How does one know what one knows? (Epistemology) and (3) How should we lead our lives? (Ethics).  Beyond Smith's philosophical naivete and reasoning errors, Smith, like all atheists, did not even begin to provide intelligible answers, based on his godless reality, in any of these areas. Smith's materialist atheism is: (1) metaphysical irrationalism (espousing the ultimate chance nature of reality); (2) provides no self-attesting theory of knowledge (rendering knowledge impossible, and thereby, Smith has no ground from which to criticize anyhthing); and (3) provides no basis for the existence of absolute morality or ethical truth (morality is not a property of material systems).  All through the debate, Smith argued in vicious circles and merely assumed the existence of human rational freedom (which is incompatible with the assumption of material monism), logic, moral laws, abstractions, conceptual reasoning -- all of which inexplicably spring out of chance and physical (material) causation (or, alternatively as in platonistic pluralism, are an incoherent plurality of independent and ultimate brute entities suspended in the "void").  As Bahnsen pointed out, all of these are problems in Smith's atheist universe, but not for Christianity. (In fact, Smith is assuming facts that are borrowed from Christian theism.) Smith's atheist presuppositions thus have been shown to be incoherent and self-contradictory on the atheist's own ground, while the Christian presupposition and Christianity is vindicated.  

Postscript

During the call-in section, Smith responded to a question regarding the Bible. Smith responded, "Well, I mean there are some decent things in the Bible, sure. There are some elegantly expressed moral maxims, that sort of thing." (emph. added.) Bahnsen, probably due to lack of time, didn't respond to this but the reply to this sort of remark is: "On what standard does Smith rely to determine morals?" Would he claim that standard is absolute and knowable? On Smith's view the moral statements of Christ would be no more authoritative than those of any other; merely subjective opinion and non-absolute. The fact that Smith likes some of them is not a basis for absolute morality. Some people like Coke, others Pepsi. Smith, like all unbelievers, is his own ultimate, and arbitrary, standard.

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1 Abstract entities, such as the laws of logic, are immaterial and not extended in space. As, such they are not empirically accessible; they are not natural objects perceived by the senses. For example, the law of deduction called "modus ponens" cannot be seen with the eyes. The question of the reality of abstract entities (especially universal and invariant concepts such as mathematics and logic) and conceptual knowledge lies at the root of the well known failures of rationalism, on the one hand, and empiricism, on the other, to provide a foundation for human knowledge. Both schools ended in skepticism regarding human knowledge. One should also consider that the modern phrase "logical empirical method" merely linguistically conjoins the two philosophical schools and thereby glosses the problems of both without solution, yet admits the distinction between the abstract and the natural. Stated in other terms, this dichotomy is also the distinction of deduction (necessary truths of reason) versus induction (contingent truths derived from generalizations of particular sense data). Bahnsen's point is that the atheist "universe" provides no intelligible account for either reason (human rational autonomy and conscious thought independent of material causation, existence and reality of universal laws of logic, etc.) or empirical knowledge/induction (given the atheist's commitment to ultimate chance and the irrational nature of the universe as embodied in quantum mechanics). On the atheist view, there is no bridging of the gap between the immaterial transcendent and unchanging truths of, say, logic or arithmetic, and the immanent and ever changing world of material flux. The problem that the atheist has with providing a justification of induction is well known -- it is a principle that cannot be deduced nor inductively derived (which is vicious circular reasoning and question begging). On the other hand, the transcendent God of Christian theism provides the intelligible answer to both deduction/reason (man is created in the image of God, the ultimate rational being and the source of man's reason -- behind the mind of man is the mind of the eternal God) and induction (God has created and faithfully sustains the cosmos ("...in Christ all things consist." Colossians 1:16-7). Further the existence of universal abstract entities, in that they are the contents of thought, are not eternal self-existent things existing in a mind-independent platonic world of ideas, but rather, the thoughts of the eternal God. They are real; and man, as the rational image of God, is to "think God's thoughts after Him," as Van Til has said. ^↩
2 Smith fallaciously used the example of the "Law of Identity" as "support" for his claim. Rather than the law of identity, one might think that the material conditional of logic ("if P then Q") would provide a more plausible support. However, it is generally known that the material conditional does not represent the concept of causality. See, for example, Paradoxes of Material Implication (in particular, see the example of switches in a series circuit in the section on "Simplification"), Material Conditional; and Causality (section titled, "Causality contrasted with conditionals"). Incredibly, Rudolph Carnap (a logical positivist) makes the philosophical error of representing causal laws via the material conditional in chapters 1 and 20 of An Introduction to the Philosophy of Science. ^↩
3 Latin, literally,"no more beyond." ^↩
4 Amazingly, Michael Martin also fatuously uses a version of the "Euthyphro dilemma" in his flawed TANG ("Transcendental Argument for the Non-existence of God").  The Euthyphro dilemma presupposes a mythological platonic reality of ultimate abstract moral laws to which all the "gods" and man are equally subject (and of which laws they somehow have knowledge) -- as such, it is contrary to the claim of Christian theism that God is ultimate.  Thus Martin's counter does not apply -- it is a straw man. It is a logical fallacy of the most egregious type to assume the truth of "not A" to refute "A." TANG as a refutation of TAG is an utter failure. TANG is not even analogous to TAG. To be analogous, TANG would need to show: (1) that the Christian conception of God is contradictory and (2) that atheism (whether materialist or platonic pluralism) provides the necessary and coherent conditions for all of human experience -- including intelligible accounts of possibility of knowledge and existence of moral absolutes.  This, of course, is something that neither Martin nor millennia of failed atheist philosophy and science has done.  In short,  TANG is not a transcendental argument and Michael Martin does not understand transcendental argumentation (at least, he fails to understand TAG).  ^↩

More on TAG

A correspondent has asked, "Is 'logic' a premise of TAG (The Transcendental Argument for God)?"¹

This question underscores the typical unbeliever's inability to grasp the issues in the debate between totally antithetical worldviews. It also suggests a general unfamiliarity with transcendental argumentation -- as it construes TAG as a deductive argument, and it seems to lapse into a standard "deductivist" view of proof, so prevalent among many unbelievers.

First, TAG is not formally a deductive argument. Deductive arguments necessarily presuppose logic. Without logic, deductive arguments could not even get off the ground. So, the answer is, no, logic per se is not a premise of TAG.² In the presuppositional defense of Christianity, we do not presuppose a merely abstract and autonomous logic, nor do we posit it as a premise of a deductive argument leading to a conclusion of a God of indeterminate character or an abstract "God of the philosophers."

Second, when it comes to the issues of the existence of logic, abstract objects, and conceptual reasoning, in general, the point of TAG is that the godless reality of atheism, on the basis of its own metaphysical presuppositions, cannot account for their existence. For instance, the existence of logic and material monism are contradictory. Laws of matter and the ultimacy of chance do not produce mentally free, conscious beings who are capable of abstract thought. Materialism cannot account for the existence of immaterial abstract entities of any type (be it logic, mathematics, or moral laws).³ The existence of logic, then, is a problem, and failure, of the atheist worldview. As I have written before, atheists cannot give a "reason for reason." As such, atheists have no metaphysical ground for their presupposition of logic. Atheists, being "epistemological loafers" as Van Til put it, will not acknowledge this. Even in the face of continued prodding, they continue to use a merely assumed autonomous logic and reason, that is, just "take it for granted." But that is question begging and an intellectually empty response. Yet, on the other hand, they will assert that man and his mind was produced by (and thereby, still ruled by) ultimately random material processes. Atheism -- by asserting the autonomy of man (and thereby, the ultimacy of the human mind) along with the ultimately chance nature of temporal facts -- is self-contradictory. Atheism provides no grounds for any of its beliefs (articles of faith, as it were); it can only be adhered to by a willful intellectual blindness.

The positive presupposition of TAG is the existence of the Triune God of Christianity who has revealed Himself in the Bible, in nature, and within man himself. God is the metaphysical ground from which all human experience is intelligible. Logic (and other abstract objects) is not a problem for the Christian theist. Behind man's reasoning is the mind of God.

To reiterate the point: logic is a problem for atheists and agnostics; it is no problem for the Christian theist.

In response to the correspondent's question, I pointed out the following as an example of presuppositions: The laws of logic are laws of rational thought; as such logic presupposes a thinking mind. In Christian theism, that ultimate mind is the mind of the eternal and personal God. Though this may be wrongly interpreted as if it were a deductive argument, it is not. It is an illustration of a presupposition that underlies and is the metaphysical ground of human logic.

The correspondent responded with the question, "Why can't that mind be mine?" Indeed, that is the question for him to answer based on a presumed godless reality! Many questions come to mind. For example, where or from what did his mind originate? Did immaterial minds irrationally spring forth de novo from matter in motion (If indeed there be minds as opposed to mere physically determined material brains)? Was there a first mind? Or, is there an infinite past of finite individual minds begetting new minds, (coming into being at birth, then vanishing into nothingness at death)? Is his mind ultimate? If not, what produced his mind? Is his mind free from physical determination (i.e., does he have rational freedom and volition)? How many unrelated (material and perhaps non-material) causal principles does the unbeliever invent to account for the existence of minds? Are those causal properties, along with matter and minds, of which they are properties, eternal, uncreated, ultimate constituents of reality?  In addition, for a materialist the question is (a) how all the biochemistry going on in every human skull (different processes in different locations) gives rise to objective non-material abstractions, such as logic, or, if not a materialist, (b) from whence all these contingent minds emerged equipped with innate and invariant logic. Those are just a few problems for starters.

Again, the question remains for atheists and agnostics to answer on the foundation of their metaphysical presuppositions. Answers that millennia of atheist philosophies have failed to supply.

I've already given the Christian answer: Mind is not his alone. The ultimate mind is the mind of the eternal God of Christian theism.

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1 The historical connection of logic to TAG stems from Greg Bahnsen's use of the presuppositional apologetic in his debate with atheist Gordon Stein where Stein couldn't support the existence of, or use and reliability of, logic on the basis of his materialism. This was a defining moment for public awareness of presuppositionalism. In a way, it is a bit unfortunate that the debate paved the way for some, including Christians, to think that the existence of logic is the only or main element of TAG (thereby focusing attention mainly on logic in conjunction with TAG). But such is not the case. TAGs challenge to unbelief is that it cannot make sense (on its own presuppositions) of any fact of human experience. Thus, one can start with logic, or language, or mathematics or moral laws (among others) to expose the unbeliever's internal contradictions and refute the unbeliever's worldview or total view of reality. ^↩

2 What is at issue in the debate between Christians and unbelievers is not merely "logic," but the conception of logic that each participant in the debate holds. Logical reasoning is necessary -- for both parties -- in the encounter of belief with unbelief. When we reason with unbelievers we, of course, employ our God-given capacity for logical thinking. The unbeliever will likewise employ logic in the debate while all along denying God. However, the unbeliever typically does not question his capacity to reason, nor ask what is the metaphysical ground of the human ability to think and reason according to abstract laws of logic. The "logic" to which the unbeliever appeals (and which is his ultimate authority) is an autonomous "logic" that exists in a void. So an appeal to a common conception of "logic" is illusory. The totally antithetical conceptions of logic (among a host of other things) are at the core of the debate. Van Til addresses this issue:

"It appears then that if there is to be any intelligible encounter between the Christian and the non-Christian, it must be in terms of the two mutually exclusive visions that each entertains. To appeal to the law of contradiction and/or to facts or to a combination of these apart from the relation that these sustain to the totality-vision of either, the believer or the unbeliever, is to beat the air. It is well to say that he who would reason must presuppose the validity of the laws of logic. But if we say nothing more basic than this, then we are still beating the air. The ultimate question deals with the foundation of the validity of the laws of logic. We have not reached bottom until we have seen that every logical activity in which any man engages is in the service of his totality-vision." (Emph. added) Cornelius Van Til, The Case for Calvinism. The Presbyterian and Reformed Publishing Company: Philadelphia, 1964. (Quoted from The Works of Cornelius Van Til, Logos Digital Edition).

As to the question of logic in the debate between totally antithetical worldviews Bahnsen writes:

"The antithesis (in principle) between the philosophical systems of unbelievers and the philosophical system of believers is so broad and basic that it even affects the way they deal with central philosophical notions like logic, possibility, and objectivity (to mention but a few). This observation should not be misunderstood. The presuppositionalist does not say that Christians and non-Christians inevitably accept and operate with completely different, specific laws of logic in their practical exercises of reasoning. Yet they do clearly disagree with each other concerning the nature, source, and authority of the laws of logic. Both worldviews may endorse and utilize the disjunctive syllogism or De Morgan's theorems, but when we inquire into what they are talking about, the evidence that is appropriate or persuasive for their claims (about syllogisms, theorems, etc.), or the necessity of the truths about logic, we get radically different answers -- which almost always betray differing convictions regarding metaphysics." (Greg Bahnsen, Van Til's Apologetic: Readings and Analysis, The Presbyterian and Reformed Publishing Company: Philadelphia, 1998. p. 280)^↩

3 It is true that there are some atheists who are not material monists -- but they are few and far between. There are idealistic monists (mind is the fundamental stuff of reality) and there are others usually referred to as "pluralists" who believe in a plurality of co-ultimate things (Roger Penrose, for example). But, in the case of the pluralists, merely asserting the existence of minds and a plurality of immaterial "platonic" entities with no coherent unity among them is question begging and provides no intelligible ground for human knowledge. In addition to being no answer to the problem of the one and the many, no atheist has given the account of what bridges the gap between the particulars of the atheist's material world with its basic chance characteristics and their eternal unchanging realm of universal "platonic" entities. As mentioned above, the existence of human minds in this worldview is also a major problem -- especially on the macro evolutionary account that human minds are no more than material brains assembled by (and thereby still controlled by) random physical processes. The dual atheist principles of human autonomy and the ultimacy of chance are contradictory.

The many problems of a platonistic conception of reality are well known, which explains why few advocate it, and won't be dealt with here. As to the idealists, which were more in vogue during Van Til's time, Van Til's writings, in particular A Survey of Christian Epistemology, provide a wealth of information on the internal contradictions of the idealists. ^↩