Rational/Irrational Dialectic

Cornelius Van Til and the Rational/Irrational Dialectic in Unbelieving Thought

Introduction

Cornelius Van Til (1895–1987), a pioneering Reformed theologian and apologist, taught that non-Christian thinking is characterized by a “rational/irrational dialectic.” In simple terms, unbelievers oscillate between rationalism – exalting human reason as ultimate – and irrationalism – embracing chance, chaos, or skepticism at the foundation of reality . Van Til argued that this dialectical tension lies at the heart of unbelieving worldviews and ultimately undermines their ability to truly know anything. In this article, we will examine how this rational/irrational dialectic manifests in unbelieving thought and why it poses a fundamental epistemological problem (a problem of knowledge). We will also consider practical implications for apologetics, comparing Van Til’s approach with alternative philosophies and frameworks. Van Til’s own writings will be our primary guide, supplemented by insights from his students (such as Greg Bahnsen) and scriptural exegesis that supports his critique of unbelieving epistemology. Throughout, we will see why Van Til insists that unbelievers live in a self-contradictory tension between rationality and irrationality – a tension that only the Christian worldview can resolve.

The Rational/Irrational Dialectic in Unbelieving Thought

Van Til observed that ever since the fall of man (Genesis 3), human thinking apart from God has been pulled between two opposite impulses. On one hand, the unbeliever wants to be rational: he wants to use logic, to find universal truth, and to subject everything (even God) to human reasoning. On the other hand, the unbeliever’s rejection of the true God forces him to base everything on irrational grounds: ultimately, he must assume a universe of chance and unknowable “brute” facts, a reality with no absolute truth or order behind it. Van Til succinctly explains this dilemma: “Unbelief is rationalistic, because it insists on the autonomy of human thought… On the other hand, unbelief is also irrationalistic, because it believes that the apparent order in the universe is ultimately based on disorder, upon chance.” In other words, the non-Christian wants to be the ultimate judge of truth (rationalism), yet also believes that reality at root has no divine order or final truth (irrationalism). These two tendencies are logically at odds – hence a dialectic or tension that runs through all unbelieving thought.

Van Til likens the unbeliever’s mindset to a see-saw oscillating between “pure rationalism” and “pure irrationalism” . The autonomous thinker swings from confidently claiming human reason can explain everything, to despairing that nothing can truly be known. This instability is the direct result of rejecting our dependence on the God of Scripture.

Historically, this rational/irrational dialectic can be observed in many philosophies. Ancient Greek thought provides a vivid example. The philosopher Parmenides argued that reality is one, changeless, and rationally comprehensible (rationalism), while his rival Heraclitus insisted that everything is flux and change (an outlook akin to irrationalism). Plato tried to reconcile this by positing two levels of reality – eternal rational Forms and a fluctuating world of sense experience – but he could never fully explain how these two interact . As Van Til notes, Plato’s “forms represent his rationalism; his irrationalism is seen in his view of the empirical world… The enduring problem of Plato’s philosophy is the difficulty of achieving any intelligible relationship between the two worlds.” In Van Til’s analysis, every non-Christian system faces a similar “two-world” problem: an ultimate rational principle (a unity, law, or mind) that cannot make sense of the ultimate irrational principle (diversity, chaos, or matter), and vice versa. The tension simply takes different forms in different thinkers. For example:

• Socrates (in Plato’s Euthyphro) dismisses the gods and seeks a rational definition of piety in itself – assuming human autonomy in determining truth. Yet he admits that “the holy” as a concept is ultimately beyond human reach, “wholly beyond the reach of human definition.” Van Til observes: “This is rationalism. But involved in this rationalism is the notion that holiness is an idea wholly beyond reach… This is irrationalism.” In Socrates’ thought, as in all unredeemed thought, autonomy produces a rationalism that contains an inescapable irrationalism.

• Enlightenment philosophy likewise split along rationalist and empiricist lines. The Rationalists (Descartes, Spinoza, Leibniz) believed in universal human reason and innate principles, while the Empiricists (Locke, Hume) grounded knowledge in sensory experience of particulars. David Hume’s radical empiricism led to skepticism – he showed that if we only trust finite experience (irrational brute facts), we cannot rationally justify universal laws of nature or causation. Immanuel Kant then tried to resolve this by combining both: he said the mind imposes rational categories on an unknowable substratum of raw experience. In Van Til’s terms, “Kant’s supposed advance… is merely that he has combined an abstract rationalism such as that of Parmenides or Spinoza with an equally abstract brute factualism such as that of the most extreme process philosophers.” Kant still ended up with a two-layer reality: an orderly, knowable phenomenal world (because our reason structures it) and a noumenal world of “things-in-themselves” that is utterly beyond our knowledge (irrational, beyond reason’s reach). Modern secular thought continues this pattern – often swinging between scientific rationalism (confidence that human science and logic can explain the universe) and postmodern irrationalism (claims that ultimate truth or meaning is unknowable, merely a matter of perspective or chaos).

Van Til argues that these oscillations are not accidental. They arise necessarily whenever man refuses to acknowledge his Creator. The “fulcrum” of the entire see-saw is the autonomous human ego – sinful man setting himself up as the ultimate reference point . Once man does this, “he will quite naturally continue to go up and down, up and down, on this see-saw.” When the unbeliever feels confident in his system, “the rationalist is up” and he claims to have defeated skepticism. But then the weaknesses of his position inevitably flip, “the irrationalist is up,” and all certainty collapses – yet not for long, as the autonomous man then formulates a new rationalistic scheme, and so on . Crucially, Van Til adds that “the rationalist and the irrationalist are really not separately existing entities at all, but rather opposite, co-existing aspects of the one and indivisible would-be self-sufficient homo sapiens.” In other words, the same unbelieving person is both a rationalist and an irrationalist at heart. These are two sides of the same coin of autonomy. Fallen humanity “introduced the rationalist-irrationalist synthesis that has marked all human thought that is not redeemed by Christ.”

Rationalism vs. Irrationalism Defined

To understand this better, let’s define the terms as Van Til uses them in the context of unbelief:

• Rationalism (Autonomy): The assertion of human reason as supreme. The rationalist impulse seeks to “penetrate exhaustively by logical insight” – to make all reality submit to man’s understanding. The unbeliever in this mode trusts in laws of logic, human science, or moral reasoning as if these operate independently of God. He might say “reason alone is the final judge of truth”. This is the sin of intellectual pride from Eden: Adam and Eve wanted the “knowledge of good and evil” on their own terms (Genesis 3:5-6), effectively “seeking ‘to be like God’” as the ultimate reference for truth . Van Til notes that unbelievers “insist that human thought is the ultimate criterion of truth and falsity, of right and wrong.” That is rationalism. It often produces systems that are very dogmatic and idealistic (trying to explain reality by a grand scheme of thought). Yet – apart from God – this confidence is misplaced, because finite human reason ends up floating on nothing. Thus rationalism by itself drives one toward the opposite pole: if man’s mind cannot actually know ultimate reality exhaustively, the rationalist is left in despair.

• Irrationalism (Chance): The assertion of ultimate unknowability – reality has no inherent order or absolute truth, so human reason is limited to a small domain or is just a pragmatic tool. The irrationalist impulse emphasizes “brute facts” (things that just exist without any rational plan or interpretation behind them) and often leads to skepticism, relativism, or nihilism. As Van Til explains, “Irrationalism rejects any form of ultimate authority and therefore must have chance as its ultimate basis. If there is no God back of time and history… then chance must rule.” The unbeliever in this mode might say “truth is subjective” or “we can’t know ultimate reality – it’s all chaos or flux.” This sounds humble, but it too is a form of autonomy: the irrationalist is “a law unto himself” in that he acknowledges no higher truth than his own momentary experience. Furthermore, Van Til incisively observes that even the statement “nothing can be known of ultimate reality” is itself a kind of absolute claim. To declare “no one may know ultimate reality” with certainty is to speak as though one has a godlike vantage point (a paradox Van Til highlights: “to say, with the irrationalist, that no man may know anything about ultimate reality is, in effect, to claim absolute knowledge of absolute reality.” ). Thus pure irrationalism self-destructs unless it is paired with some rational principle to defend it – and so the unbeliever is back to rationalism in some form.

We see, then, why these two tendencies always come in pairs. Every purely rationalistic claim by the unbeliever (e.g. “human science can explain everything important”) rests on an irrational escape (because why assume the universe is fully intelligible by our minds, if it arose by unguided chance?). Conversely, every purely irrational claim (“truth is chaos, nothing is certain”) conceals a rationalistic presumption (the claim itself is put forward as a certain truth about reality!). Van Til summarizes this merry-go-round: “Apostate man discovers that his purely rationalistic ideal of knowledge – complete adequation of thought and being – leads to the loss of his own identity.” In other words, if he actually could explain everything exhaustively, he would reduce himself to a mere object (a determined part of the machine, no freedom). Seeing this, fallen man “turns, in desperation, to the idea of pure irrationalism, asserting that no one may know ultimate reality anyway” . Yet this too is unstable: “Such ‘pure irrationalism’ cannot be maintained except as the dialectical counterpart of ‘pure rationalism.’” The end result: “the apostate man see-saws back and forth between pure rationalism and pure irrationalism without ever coming to rest.”

This analysis is not merely abstract; it describes the inner turmoil of the unbelieving heart and mind. One moment the unbeliever speaks as a rationalist, confident in logic and “common sense.” The next moment he embraces irrationalism, saying truth is a matter of opinion or that human reason is impotent. Presuppositional apologist Greg Bahnsen (a disciple of Van Til) noted that the unbeliever “wants to have his cake and eat it too.” For example, an atheist might argue in one breath that “anything is possible in a universe of chance” (no absolute moral or logical norms – an irrationalist streak), but then insist “everyone must bow to the laws of logic and science, which even God would have to obey if He existed” (a rationalist streak) . He proclaims total freedom of thought, yet promptly binds himself (and others) to iron-clad rational norms. This “vacillation between these two poles” is the hallmark of unbelief. Van Til would say that the unbeliever must oscillate because he is living in God’s world while denying God. He cannot escape knowing the truth entirely – since he is made in God’s image and lives amidst God’s clear revelation in nature – so he will have moments of “borrowed” rational insight. But neither can he escape the consequences of his rebellion – the world will not make ultimate sense without God – so he will have swings into irrationalism and skepticism. The resulting picture is an “epistemological rollercoaster”: bold claims of certainty one minute, and radical uncertainty the next.

The Rational/Irrational Dialectic and Epistemology

Epistemology is the study of knowledge: how we know what we know. Van Til’s critique of the rational/irrational dialectic is essentially an epistemological critique of unbelief. He contends that non-Christian worldviews, by rejecting the God of the Bible, undermine the very foundations of knowledge and end up in incoherence. Let us unpack how this works and why Van Til says only the Christian framework can escape the dilemma.

1. No Neutral Knowledge: Van Til insists that there is no neutral or autonomous way of knowing. All human knowledge rests on presuppositions – foundational beliefs accepted by faith. The Christian builds on the presupposition of the self-revealing triune God; the non-Christian builds on some aspect of creation treated as ultimate (matter, mind, self, etc.) . Because of sin, the unbeliever will not acknowledge God, and so his starting point is a false presupposition of autonomy (he assumes he can find truth while ignoring God). This false start immediately produces the twin problems: rationalism (he will absolutize his own mind or some finite principle) and irrationalism (he will ultimately rest that principle on randomness or brute facts he cannot account for). In epistemological terms, the unbeliever either claims far too much for human knowledge (pretending to an absolute standpoint he doesn’t have), or far too little (reducing knowledge to conjecture, with no divine guarantee of truth). Often he does both inconsistently. Van Til illustrates this using Kant: “The irrationalism of our day is the direct lineal descendant of the rationalism of previous days. The idea of pure chance has been inherent in every form of non-Christian thought in the past. It is the only logical alternative to the position of Christianity according to which the plan of God is back of all.” All unbelieving epistemologies, at root, toggle between human “plan” or no plan at all. Either man’s plan, mind, or categories are assumed to make sense of experience (rationalism), or – seeing the inadequacy of that – one falls back on “pure factuality”, a universe of “chance” where knowledge becomes ultimately impossible (irrationalism). Van Til famously said that unbelievers “know in their heart of hearts” the God who created them, but they “suppress the truth” (Rom 1:18) and become “vain in their reasoning” (Rom 1:21). The Apostle Paul’s verdict is exactly Van Til’s point: “Claiming to be wise, they became fools, and exchanged the truth about God for a lie.” Unbelieving thought claims wisdom (the rationalist pride) yet turns to foolish falsehood and idolatry (the irrationalist result). The clarity of God’s revelation means the unbeliever has no excuse for his folly, but the corruption of his heart means he will spin out ever-new rationalizations to avoid God – even at the cost of being inconsistent .

2. The “Noetic” Effects of Sin: Reformed theology teaches that sin affects the mind (the Greek word nous – hence “noetic” effects). Van Til applies this to explain the epistemological tension. Because of sin, the unbeliever is at war with himself. He still possesses the imago Dei (image of God) with its rational capacities; he still lives in a universe absolutely governed by God’s order (making knowledge possible); and he still, at some level, knows God is real (see Rom 1:19-21). This pulls him toward rationality – he cannot help using logic, expecting an orderly world, and affirming some truths. Yet he is morally bent against God and will not honor Him. Thus the unbeliever must interpret the world in a way that excludes the very source of its intelligibility. The result is an inner contradiction: “they did not see fit to acknowledge God, [so] God gave them up to a debased mind” (Rom 1:28).  Their thinking becomes “futile” and their understanding “darkened” (Eph 4:17-18), even as they might be geniuses in other respects. Van Til sometimes described the natural man as “epistemologically schizophrenic” – in his mind “there is both recognition of God and denial of God at the same time” (to use the language of Romans 1: “knowing God… they did not honor Him as God”). This produces endless rationalization: the unbeliever “knows” the truth but “suppresses” it (Rom 1:18), and thus he must fabricate elaborate false explanations for reality. Those explanations oscillate between confident over-claiming and cynical under-claiming about knowledge. Reformed apologist John Frame (a student of Van Til) summarizes: “Unbelievers have to live in God’s world even as they deny Him, so they both know and don’t know God at the same time. Van Til shows that the unbeliever can in one sense have genuine knowledge, yet in another sense be ‘a fool’ who has ‘no knowledge’ (cf. Ps. 14:1).” This puzzling state leads to the pattern of rationalism/irrationalism. The unbeliever at times borrows capital from the Christian view (using logic, science, moral intuition that only make sense if a rational God made a rational, moral universe), but at other times he asserts his independence and plunges into skeptical doubt or absurdity. He cannot consistently live out pure irrationalism (or he would literally “know nothing”), yet he cannot attain the true coherence that comes only by “thinking God’s thoughts after Him.” The Bible itself portrays this inner tension. For example, Proverbs 1:7 declares: “The fear of the Lord is the beginning of knowledge; fools despise wisdom and instruction.” According to Scripture, reverence for God is the foundational principle of genuine knowledge – apart from it, one becomes a “fool,” no matter how educated or clever. This aligns perfectly with Van Til’s thesis: unbelievers, by despising God’s wisdom, reduce themselves to foolishness. Their knowledge has a foundational crack; they may build impressive intellectual structures, but the structures rest on sand. In contrast, “In [Christ] are hidden all the treasures of wisdom and knowledge” (Colossians 2:3), and “the fear of the Lord is the beginning of wisdom” (Psalm 111:10). Van Til’s unapologetic stance is that Christian theism provides the only philosophically cogent basis for knowledge. All non-Christian systems, when examined, collapse into the rational/irrational see-saw, “destroying all basis for intelligible predication” (i.e. they cannot give a reasoned account for the meaningful use of language and logic about the world).

3. The One and the Many – Unity and Diversity: An important aspect of epistemology is how we relate universals (abstract laws, categories, unity) and particulars (concrete facts, diversity). Van Til often connected the rationalism/irrationalism problem to this classical “one and many” problem. Rationalism tends to stress the One (a unifying rational principle) at the expense of diverse reality, whereas irrationalism exalts the Many (chaotic plurality) without an underlying unity. For knowledge to be possible, we need both: a world with order (so things have identities and follow laws) and diversity (so things are distinct and observable, not one blank uniformity). Non-Christian philosophies, says Van Til, “have admittedly experienced great difficulty” in getting unity and diversity to harmonize . Either they end up with an “abstract universal” that obliterates individual things (e.g. extreme rationalists might say everything is ultimately one substance or idea), or with abstract, unrelated particulars that we cannot truly know . Van Til’s bold claim is that only the doctrine of the Trinity provides the solution: “In the Christian doctrine of the triune God, we have a concrete universal: in God’s being there are no particulars not related to the universal, and no universal not fully expressed in the particulars.” The Father, Son, and Holy Spirit are distinct persons (diversity) yet one being (unity), eternally in relationship. Therefore, ultimate reality is not an impersonal rational idea (which would make love, personality, and change meaningless), nor an unknowable chaos of “many” (which would make truth and reason impossible). Ultimate reality is the personal triune God, who gives creation both unity and diversity. Augustine long ago said that only in the Trinity can we avoid making an idol of either unity or plurality . Van Til builds on this: the rationalist idolizes unity (but then can’t account for real differences and change), the irrationalist idolizes disjointed plurality (but then can’t account for logical order or universal truth).  Christianity alone, he argues, honors the equal ultimacy of the One and the Many in God’s nature, which then is reflected in creation as a cosmos of ordered diversity. This might sound abstract, but it has everyday epistemological consequences: it means Christians have a reason to expect the world to be intelligible (reflecting God’s rationality) and to expect there will remain depths of mystery (since only God’s mind is omniscient, and we are creatures). We neither demand exhaustive understanding (which would be rationalism) nor embrace despair of understanding (irrationalism). We receive truth as revelation from the God who harmonizes rationality and mystery in His own being . Van Til put it this way: “Only if one presupposes God as the one in whom rationality and being are coterminous and coextensive can he use the laws of logic at all.” If we acknowledge our creaturely status and God’s absolute character, we have a foundation for logic and reason (because the universe is coherent in God’s plan), and we have the humility not to misuse logic by trying to judge God or explain away genuine mysteries (we accept that God’s thoughts are higher than ours). The unbeliever, lacking this foundation, either idolizes logic (trying to make his finite mind the measure of all things) or dismisses logic when it inconveniences his autonomy. Van Til drily notes: “The a priori of any non-Christian thinker will eventually lead to empiricism [irrationalism]… The a priori of Plato or some other non-Christian philosopher cannot safeguard against skepticism.” He saw, for instance, that pure logic without the Christian God ends in self-defeating conclusions (as Kant showed), and pure fact-accumulation without a divine order ends in “utter darkness” (no way to interpret those facts). The Christian, by presupposing the God of Scripture, avoids both extremes and thus can have genuine knowledge (though not exhaustive knowledge). This is a profound epistemological claim: that theology – specifically Trinitarian theology – is the key to epistemology. Van Til was unapologetic in asserting this, following thinkers like Kuyper and Bavinck who said that in Thy light we see light (Psalm 36:9).

In sum, Van Til’s teaching on the rational/irrational dialectic reveals an internal inconsistency at the heart of unbelieving thought: the unbeliever craves absolute certainty (because he is made in the image of a certain God) yet also wants absolute autonomy (which would leave only uncertainty). He cannot have both. Epistemologically, he is torn between being “like God” in knowledge and being a mere product of cosmic accident. This tension infects all his theories of knowledge. By contrast, the Christian epistemology that Van Til defends begins with humble submission to God’s self-revelation. The Christian does not pretend to exhaustively know everything – in fact, accepting mystery at God’s say-so is part of faith – but he has a firm basis for the things he does know, because God has made his mind and the world to correspond (in a limited, analogical way). Van Til often quoted Proverbs 1:7 (cited above) and Colossians 2:3 to show that true knowledge is rooted in acknowledging the Lordship of Christ. When we do, we escape the despair of irrationalism (since God’s world is orderly and meaningful) without falling into the hubris of rationalism (since our wisdom is derivative and dependent on God’s). Scripture consistently contrasts the “wisdom of the world” with the wisdom of God. For example, “Has not God made foolish the wisdom of the world?” Paul asks . “For since, in the wisdom of God, the world did not know God through wisdom [human wisdom], it pleased God through the folly of what we preach to save those who believe.” God in salvation destroys the pretensions of human wisdom, exposing it as foolish, and calls us to trust His revelation (even when it offends worldly rationalism, as the cross of Christ did). Yet this gospel is not irrational – rather, it is “the power of God and the wisdom of God” to those who are called . The implication is that worldly reasoning, unaided by faith, inevitably misses the ultimate truth (“the world through its wisdom did not know God”), confirming Van Til’s point. Unbelieving epistemology lives in a self-defeating tension; only by starting with God can we have a coherent theory of knowledge.

Practical Implications for Apologetics

Van Til’s analysis of the rational/irrational dialectic was not merely theoretical. It was developed in service of Christian apologetics – the defense of the faith. If the unbeliever truly is in a state of epistemological tension, then the apologist must address not just isolated doubts or questions, but the very foundation of the unbeliever’s thinking. Van Til therefore advocated a presuppositional or transcendental method of apologetics, sometimes called the method of “indirect” proof . Instead of starting by appealing to supposedly neutral evidence or autonomous reason (which would play into the unbeliever’s rationalist pretensions), Van Til said we must “challenge the unbeliever’s presuppositions” and expose the dialectic at work in them. Practically, this means the apologist does two crucial things:

• Press the Antithesis: The apologist lovingly yet firmly forces the unbeliever to see the inconsistency of his worldview. This is often done by performing an internal critique – temporarily “adopting the unbeliever’s presuppositions for the sake of argument” and showing that they lead to absurdity (either to radical skepticism or to logical self-contradiction). We “answer a fool according to his folly” (Prov 26:5) so that he may not be wise in his own eyes. For example, if a skeptic claims “Truth is relative; there are no absolutes,” the apologist can point out that this very statement is asserted as an absolute truth – a self-contradiction. If a secular scientist says, “I only trust what is empirically proven,” one can gently ask if that principle itself was empirically proven (it wasn’t; it’s a philosophical presupposition – thus a blind spot in strict empiricism) . In ethical discussions, if a relativist denies moral absolutes but then indignantly condemns some injustice as “wrong for everyone,” he has momentarily assumed a moral absolute, contrary to his system. These are examples of pointing out how the unbeliever borrows from Christian premises (truth, logic, moral absolutes) while verbally denying them. Van Til liked to say the unbeliever “must sit on the lap of God to slap His face.” He can’t even raise an objection against God without using God-given reason and moral instincts, which only make sense if God is real. The goal is to help the unbeliever recognize this “borrowed capital” and the impossibility of the contrary. In Van Til’s words, we must show that without the Christian God, “no meaning, intelligibility, or predication is possible”” . Greg Bahnsen calls this “holding up the mirror” to the unbeliever’s worldview, showing him the irreconcilable “contradiction he is caught in: trying to hold to both rationalism and irrationalism”, and thus “not really able to make any reasonable sense of the world.” This often involves highlighting the preconditions of knowledge that the unbeliever is unwittingly relying on – things like logical laws, scientific uniformity, human dignity and mind – and asking how his worldview accounts for them. Bahnsen, in a famous debate with atheist Gordon Stein, did exactly this: he pressed Dr. Stein on how a materialistic, chance universe could account for the universal, immaterial laws of logic. Stein had no sufficient answer – he alternated between calling logic a human convention (which would make it arbitrary, undermining his own arguments) and treating logic as an inviolate truth (which did not fit his atheistic worldview). Bahnsen concluded that on atheistic presuppositions, “the atheist worldview cannot allow for laws of logic, the uniformity of nature, the ability for the mind to understand the world, and moral absolutes.” In short, if the atheist’s assumptions were true, science and reasoning themselves would crumble into irrationality – a potent demonstration of Van Til’s thesis. This transcendental style of argument doesn’t merely win a debate point; it aims to convict the unbeliever that his mind is at enmity with God and generates only futility (Romans 8:7, Ephesians 4:17). It exposes the “ethical” dimension of knowledge – that it’s not lack of evidence that ultimately keeps him from God, but a rebellious mindset that distorts his entire reasoning process.

• Present the Christian Worldview as the Remedy: Having shown the problem of the unbeliever’s position, the apologist then proclaims the Christian answer – not just as one more “better theory,” but as the necessary foundation that makes sense of our experience. We “answer the fool according to his folly, lest he be wise in his own eyes” (to humble him), but we also “do not answer the fool according to his folly, lest we be like him” (Prov 26:4). That is, we refuse to adopt unbelieving assumptions as the actual truth. We explicitly stand on the Christian presupposition from the outset, and invite the unbeliever to see how within this framework, the rational and the particular are reconciled. We argue “indirectly” by “showing the impossibility of the contrary” – demonstrating that unless Christianity is true, you can’t prove or explain anything at all . For instance, after challenging the unbeliever’s view of logic, we can explain that in the Christian worldview, logic is not a random human convention but reflects the orderly mind of God (and thus is reliable and universal) . The uniformity of nature is not a freak accident but is guaranteed by God’s faithful governance (Genesis 8:22, Jeremiah 33:25). Human reasoning, though finite, is trustworthy in principle because we are made in God’s image to reflect His rationality (our minds are fashioned to “think God’s thoughts after him,” albeit in a limited way). Morality is not a mere preference but rooted in God’s holy character and revealed law. In short, we present Christian theism as the coherent, life-encompassing truth that accounts for logic, science, morality, beauty, and everything that the unbeliever inconsistently enjoys or affirms in life. Van Til called this “reasoning by presupposition” – we contrast the presuppositions and their consequences. The unbeliever’s presupposition of autonomy leads to an unlivable breakdown (a reductio ad absurdum). The Christian presupposition of the triune God, by contrast, leads to a worldview that can support human knowledge and experience without self-contradiction. As Van Til put it, the apologist must make clear that the debate is “not just a clash of isolated facts or arguments, but a conflict of whole worldviews.” And only the Christian worldview can do the job of worldview – providing the preconditions of intelligibility. This approach is often termed the Transcendental Argument for God (TAG): it argues that God’s existence (and the truth of Christian revelation) is the transcendental precondition for knowledge and rational thought. Bahnsen summarized TAG as: “the proof of God’s existence is that without Him, you couldn’t prove anything.” Instead of starting on the unbeliever’s turf (which is tainted by the rational/irrational dialectic), we start on the Bible’s turf and show that the unbeliever already depends on our turf whenever he says anything meaningful. This method turns the tables: the Christian, not the unbeliever, puts the opponent on the defensive about his theory of knowledge and reality.

In practice, an apologist using Van Til’s method will often point out the “two horns” of the unbeliever’s dilemma. Greg Bahnsen was adept at this two-step. For example, if an unbeliever leans rationalist (“I trust human reason, I’ll only believe what I deem plausible”), the apologist may highlight how this leads to skepticism – for instance, on autonomous grounds one cannot even justify inductive inference (as Hume showed) or the universal applicability of logic or morals. But if the unbeliever then leans irrationalist (“Well, we can’t be sure of truth; perhaps everything is relative or absurd”), the apologist points out that he is nonetheless making truth-claims (even the claim of relativism is offered as a true insight) and that in practice he relies on rational order (he expects his reasoning in conversation to be meaningful, expects the microphone to work based on natural law, etc.). Thus the apologist alternately refutes the unbeliever’s “pretended rationalism” (showing it would lead to absurdity) and his “pretended irrationalism” (showing he cannot actually live or think that way even for a moment) . Francis Schaeffer (though not as strictly presuppositional as Van Til) employed a similar strategy of pushing people to the logical conclusions of their worldview (“taking the roof off”) and then contrasting the despair of a life without absolutes to the hope and coherence of the Christian outlook. Schaeffer often spoke of modern man having to take an “upper story leap” into non-rational meaning because his purely rationalistic “lower story” couldn’t provide values – another way of describing the rational/irrational tension. Van Til’s unique contribution, however, was to rigorously ground this analysis in Reformed theology and to insist that the apologist never compromise on the authority of Scripture and the need for regeneration. Ultimately, no one leaves the irrational/rational merry-go-round except by God’s grace opening their heart to the truth. Yet our task is to make the folly of unbelief manifest (Prov 26:5) and to commend the wisdom of God (Ps 19:7, 1 Cor 1:24). Apologetics for Van Til is not about winning intellectual games; it’s about presenting the antithesis between belief and unbelief clearly, so that the unbeliever might see the stark choice before him: continue in futile thinking, or humbly submit to the revelation of God in Christ. Van Til famously said that at the end of the day, “There are no brute facts, only interpreted facts.” The question is: will we interpret facts rightly under God’s authority, or wrongly under man’s alleged autonomy? The rational/irrational dialectic in unbelieving thought is the tragic result of interpreting facts wrongly – interpreting the world “without regard to God” . The task of the apologist is to lovingly expose that error and invite the unbeliever to come under Christ’s lordship in thought, wherein the turmoil of irrationalism and the arrogance of irrationalism are both forsaken.

Scriptural Exegesis Supporting Van Til’s Critique

Van Til’s apologetic stance is deeply rooted in Scripture. He often said he was simply applying the Reformed theology of total depravity, the noetic effects of sin, and the sovereignty of God to the realm of thought. Let’s consider some key biblical teachings that reinforce the idea that unbelievers live in a self-contradictory tension between rationality and irrationality:

• Romans 1:18–25: This is a foundational text for Van Til. Paul teaches that God’s existence and nature are clearly revealed through creation, “ever since the creation of the world, in the things that have been made” (Rom 1:20). Thus unbelievers do have knowledge – “what can be known about God is plain to them” (1:19). Yet, they suppress the truth in unrighteousness (1:18). They “did not honor him as God or give thanks, but they became futile in their thinking, and their foolish hearts were darkened” (1:21). This describes the tragic inversion: they possess truth (at least enough to render them “without excuse”), but by turning away from it, their reasoning becomes futile. They still claim to be wise – “claiming to be wise, they became fools” (1:22) . They exchange the truth of God for a lie (1:25) . Here we see both elements of the dialectic: The sinners claim wisdom (a semblance of rationality) but embrace idolatry and falsehood (irrationality). The Greek word for “fools” in verse 22 is môrainô (from which we get “moron”) – meaning they became dull, stupid in their reasoning. This folly is not intellectual inability (some of the most “brilliant” philosophers are among those who don’t honor God) – it is a moral and spiritual folly, an emptiness and inconsistency in their reasoning when measured against God’s truth. Van Til frequently referenced this passage to assert that unbelievers have an ontological knowledge of God (they are inescapably confronted with Him), but suppress it epistemologically . Thus they end up with lots of “vain imaginations” (KJV of v.21) – elaborate worldviews that ultimately are pointless and self-defeating. Romans 1 provides the theological explanation for why the rational/irrational dialectic exists: fallen humanity knows the truth but doesn’t want it, so they twist their thinking into knots to avoid the sovereign Creator, leading to intellectual futility. Van Til’s charge that “all non-Christian thought is inherently self-contradictory” is essentially a paraphrase of “professing to be wise, they became fools.”

• 1 Corinthians 1–2: Paul here contrasts human wisdom with God’s wisdom. “Where is the one who is wise? … Has not God made foolish the wisdom of the world?” (1 Cor 1:20) . In the gospel, God chose what the world calls “foolish” to shame the “wise,” so no human can boast (1:27-29) . “The world through its wisdom did not know God” (1:21) – meaning all the pinnacle of man’s rational striving failed to attain the most important knowledge (knowing God). This again underscores Van Til’s point: start from man’s wisdom alone, and you end not with true wisdom but with failure (“did not know God”) and ultimately folly (“God made foolish the world’s wisdom”). In 1 Corinthians 2:14, Paul adds that “the natural person does not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned.” The unbeliever in his irrationalist mode regards God’s truth as foolish – yet in so doing, he ironically becomes the fool. Isaiah 44:20 depicts idolaters as feeding on ashes, “a deceived heart has turned him aside… he cannot say, ‘Is there not a lie in my right hand?’” The blindness of unbelief is such that one holds a lie in hand but cannot even recognize it. Van Til saw in such verses the self-deception of sin, which inevitably leads to irrationality (believing lies, contradicting oneself). Meanwhile, “Christ the power of God and the wisdom of God” (1 Cor 1:24) stands as the solution – those who are called (by grace) find in Christ the true wisdom that puts all the philosophers’ quests to shame. This affirms that no intellectual effort will rightly grasp reality if it’s not founded on Christ. Van Til echoes this: without presupposing Christ, the unbeliever is left with only paradoxes and puzzles. Greg Bahnsen often pointed to 1 Corinthians 1 to remind apologists that we must not cater to the autonomous demands of unbelievers (as though the gospel must measure up to their independent standards). Instead, we confront them with the fact that their standards themselves are corrupt and bankrupt – God has made their “wisdom” look foolish by salvation through the cross. The rationalist Greeks scoffed at the cross as irrational; the Jews demanded miraculous signs on their terms – but God answered both with something that exposed their pride. Likewise, a Van Tilian apologist will press that the unbeliever’s whole way of approaching knowledge is prideful and must bow to God’s revelation.

• Proverbs and Psalms on Foolishness: The Old Testament wisdom literature repeatedly contrasts the wise (who fear the Lord) with fools (who reject instruction). Psalm 14:1 famously declares, “The fool says in his heart, ‘There is no God.’” Notably, it’s a heart issue – a moral stance – not a comment on IQ. Yet this “practical atheism” is branded as foolish. Why? Because, as Proverbs 9:10 reiterates, “The fear of the Lord is the beginning of wisdom.” To deny God is to cut oneself off from the source of wisdom, resulting in folly. Van Til’s apologetic aims to show the unbeliever that in saying “no God,” he inevitably descends into intellectual folly somewhere – he loses the basis for coherent thought. The book of Proverbs also has the two seemingly paradoxical instructions we mentioned: “Answer not a fool according to his folly, lest you be like him… Answer a fool according to his folly, lest he be wise in his own eyes” (Prov 26:4-5). The Van Til approach embodies this: we refuse to adopt the unbeliever’s foolish starting assumptions (we won’t be “like him”), yet we will turn his assumptions against him in argument to expose their folly (so he stops being “wise in his own eyes”). This is exactly the rational/irrational dialectic at work: the unbeliever is wise in his own eyes (rationalism) yet fundamentally walking in folly (irrationalism). The apologist’s task, as per Proverbs, is to break that pride by showing the folly – but to do so without ourselves abandoning the reverence for the Lord that is true wisdom. In practice, that means staying true to Scripture’s authority in our defense (not granting that human reason is the ultimate authority) and using a method that depends on God’s truth rather than the unbeliever’s false assumptions. Van Til would argue that classical apologetic methods that appeal to “neutral” reasoning risk violating Proverbs 26:4 – they end up answering the fool according to his folly by treating his autonomous reason as valid, and thus the apologist can become like him (adopting a shared autonomy and reducing God to a probability). By contrast, Van Til’s method strives to fulfill Proverbs 26:5 – to refute the unbeliever on his own terms (showing where they lead) – while ultimately calling both parties back to God’s terms.

• Acts 17:16–34: In Paul’s sermon at Athens, we have an example of confronting pagan philosophers. Paul points out their inconsistency: they worship an “unknown god” alongside all their other objects of worship. He then proclaims the true God as the one they actually depend on: “He himself gives to all mankind life and breath and everything… In him we live and move and have our being” (Acts 17:25,28). Even some of their poets had groped at the truth (“we are his offspring”), yet they failed to know God rightly. Paul’s approach resonates with Van Til’s: he doesn’t grant the Greeks’ assumptions, but rather challenges their ignorance and calls them to repentance from idolatry. He effectively says their worldview has a gap (an “unknown god” they acknowledge) which is actually filled by the very God they’ve been avoiding. This is analogous to showing the unbeliever that the rational order and blessings he enjoys come from the God he doesn’t know – the “Unknown God” whom we declare. Paul’s approach is worldview confrontation, not simply adding Jesus onto their philosophy. He actually undercuts the Greeks’ rationalist pride by mentioning the resurrection (at which point some mocked – showing their irrational rejection of what they didn’t even fully hear out). Van Til loved Acts 17 as a model of not flattering the Athenian intellect but challenging it at core.

Finally, Ephesians 4:17-18 is worth noting: “You must no longer walk as the Gentiles do, in the futility of their minds. They are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart.” Here Paul gives a diagnosis of the Gentile (pagan) mind: it suffers futility, darkness, and ignorance, rooted in a willful hard heart. This does not mean unbelievers can’t be brilliant in various fields, but that in terms of ultimate truth (knowing God and interpreting reality correctly) their thinking is vain. Van Til’s rational/irrational analysis is essentially describing this state of futility. The Gentile philosophers were not few in number, nor lacking ingenuity – yet Scripture judges their cumulative work as darkness compared to the light of God’s revelation. Psalm 36:9 says, “For with You is the fountain of life; in Your light do we see light.” Only by God’s light (truth) can we correctly perceive any other light. Therefore, when people turn from God’s light, they inevitably end up in some form of darkness, however sophisticated. The “dialectic” of unbelief is darkness posing as light, and light rejected as darkness (see Isaiah 5:20).

Van Til’s claim that unbelievers are living out a contradiction (between what they know deep down and what they profess outwardly) is mirrored in Romans 1 and other passages. His insistence that apologetics must address the unbeliever’s presuppositions and not just isolated arguments comes from the biblical emphasis that the basic posture of the mind (“set on the flesh” vs “set on the Spirit” – Rom 8:5-7) determines one’s acceptance of truth. No amount of evidence can persuade the determined rationalist who would rather be irrational than bow to God; conversely, no skeptic is truly consistent in his skepticism, because being in God’s image he cannot help but affirm some truth. The role of the apologist, then, is similar to the role of the prophet exposing idolatry – showing the unbeliever that the “gods” he trusts (whether human reason, science, political ideologies, etc.) are incoherent and empty, and that he is “without excuse” (Rom 1:20) for not worshiping the true God who made reason reasonable and made truth knowable.

Conclusion

Cornelius Van Til’s teaching on the rational/irrational dialectic provides a penetrating diagnosis of unbelieving thought: it is double-minded (James 1:8) – oscillating between an illusion of intellectual self-sufficiency and the abyss of meaninglessness. This analysis is not intended to belittle unbelievers (who often sincerely strive for truth), but to lay bare the spiritual condition affecting their thinking. Van Til, writing from a solidly biblical and Reformed perspective, reminds us that the battle for truth is not fought on a neutral field. Unbelief involves an ethical rebellion that shows up in one’s epistemology as well. The rationalist impulse in unbelievers reflects the residual image of God (a distorted sense of the necessity of universal truth), while the irrationalist impulse reflects the sinful desire to flee from God’s truth into intellectual autonomy. Tragically, autonomy yields only confusion. As Greg Bahnsen expanded, the unbeliever’s thinking is an “epistemological tension” – like an elastic band stretched between two poles – which inevitably snaps back and forth . The task of the Christian apologist is to point out this tension graciously but firmly, demonstrating that only by surrendering autonomy and acknowledging the God of Scripture can one find rest for one’s mind.

Van Til’s approach stands in contrast to classical and evidential apologetics that might concede too much to “neutral” reason. Instead of presenting Christianity as probably true by the world’s standards, Van Til presents it as certainly true on its own, and the very basis for intelligibility – the precondition for rational thought. This approach, while radical to some, finds resonance in the history of Christian thought: Augustine’s motto “I believe in order to understand,” and Anselm’s “faith seeking understanding,” already recognized that reverent submission to God is the starting point of knowledge, not the conclusion of an argument judged by autonomy. Van Til applies this consistently, showing that any departure from that starting point leads to an inner dialectic of folly. The positive flip-side of Van Til’s critique is a robust confidence in the coherence of Christian theism. Rather than being anti-rational, Van Til’s apologetic is in fact deeply concerned with true rationality – reasoning on the firm foundation of God’s revealed truth, rather than the “vain reasoning” built on human pride. He effectively says to the unbeliever: “Abandon your rebellion, and you do not lose reason – you regain it, grounded in the very source of Reason himself.” As Jesus is the Logos (John 1:1), the divine Reason who gives light to everyone (John 1:9), it is only by walking in His light that we escape the irrationalism of darkness (John 8:12).

In conclusion, Van Til’s teaching on the rational/irrational dialectic reveals that unbelieving thought lives on borrowed time and borrowed truth. It cannot be ultimately consistent or epistemologically sufficient. This insight drives the apologist to refuse any compromise on God’s authority in the realm of knowledge. It also drives us to compassion: the unbeliever is not an enemy to be mocked, but a lost soul ensnared in a maze of his own making – “deceived and being deceived” (2 Tim 3:13). The Christian apologist, armed with Van Til’s approach, seeks to tear down intellectual strongholds and take every thought captive to obey Christ (2 Cor 10:4-5), liberating the unbeliever from the futile cycle of rationalism and irrationalism. Van Til’s ultimate goal was not simply to win arguments but to present the Christian worldview in all its God-glorifying splendor as the only way out of the epistemological impasse. In the gospel of Christ, the light of reason and truth dawns, and the divided mind of sinful man can be made whole. As the Apostle Paul wrote, “Do not be conformed to this world, but be transformed by the renewal of your mind” (Rom 12:2). The renewed mind is one that acknowledges God in all its thoughts, thus escaping the rational/irrational dialectic and finding unity of truth in the One who is “the way, the truth, and the life” (John 14:6).

Sources:

• Cornelius Van Til, The Defense of the Faith (Philadelphia: P&R, 1955) .

• Cornelius Van Til, Christian Apologetics (Phillipsburg: P&R, 2003), 163–164 .

• Cornelius Van Til, Who Do You Say That I Am? (Presbyterian and Reformed, 1975), p. 24 .

• Cornelius Van Til, “The Rationalist-Irrationalist Synthesis,” in The Sovereignty of Grace .

• Greg L. Bahnsen, Van Til’s Apologetic: Readings & Analysis (Phillipsburg: P&R, 1998) .

• Greg L. Bahnsen, Always Ready: Directions for Defending the Faith (Atlanta: American Vision, 1996).

• John M. Frame, Cornelius Van Til: An Analysis of His Thought (Phillipsburg: P&R, 1995) .

• The Holy Bible, Romans 1:18–25 ; 1 Corinthians 1:18–31 ; Proverbs 1:7 ; Ephesians 4:17–18, etc.