Author: L. Silas Sterling

The average person might be surprised to learn there are several ways to understand what truth means. Philosophers as a group have contemplated the idea for quite some time. It appears to me that the general public—a majority of it, at least—thinks that truth is simply that which corresponds to the facts. This is roughly what philosophers define as the Correspondence Theory of Truth.

To most of us in our day-to-day lives, this feels like plain common sense. If someone tells you, “It’s raining outside,” your immediate instinct is to look out the nearest window. If water droplets are actively striking the glass, the statement is true. If the sky is clear and dry, the statement is false. We test words against physical reality, operating on the intuitive assumption that an objective world exists outside our heads and that our linguistic statements are true only when they accurately mirror those physical facts.

This clean, reassuring view underpins much of human infrastructure. It forms the bedrock of our legal system, where courthouses demand physical evidence and eyewitness testimony to establish what “actually happened.” It drives empirical science, where hypotheses live or die based on repeatable experimental data. It even governs our routine daily errands—when you follow a recipe, check a train schedule, or consult a technical manual, you expect those written instructions to correspond directly to how physical ingredients react, how trains move through space, or how mechanical parts fit together.

However, if you step into a room full of professional epistemologists—philosophers who spend their careers studying the nature and limits of human knowledge—you quickly discover that correspondence is only one piece of a much larger, surprisingly contentious puzzle. Over centuries of intense debate, thinkers have realized that defining “truth” strictly as a direct mirror of external reality introduces profound metaphysical headaches.

As a result, philosophy offers several distinct frameworks for understanding what truth actually is—and understanding these frameworks reveals a great deal about why our modern public discussions feel so deeply broken.

The Four Major Theories of Truth

In formal philosophy, the study of truth falls under what is known as alethic theory (derived from aletheia, the Ancient Greek word for truth or un-hiding). Rather than asking which specific claims happen to be true, alethic theories ask a deeper question: What underlying property does any statement possess when we label it “true”?

Historically, four primary theories have dominated philosophy.

Theory	Core Premise	Practical Application	The Philosophical Catch
Correspondence	Truth matches an independent physical reality.	Physical sciences, legal evidence, everyday verification.	We cannot step outside our sensory apparatus to check raw reality directly.
Coherence	Truth is how well a claim fits logically into an established system.	Formal logic, pure mathematics, complex legal codes.	A fantasy world or conspiracy theory can be 100% coherent yet completely false.
Pragmatic	Truth is defined by its function—what yields useful results in practice.	Scientific modeling, engineering, predictive tools.	A placebo or a useful lie can produce positive results without being factually true.
Deflationism (Later Wittgenstein)	“Truth” is not a physical property; meaning comes from use in a Language Game.	Grammatical efficiency, ordinary speech, contextual clarity.	Leaves us without a structural definition for why truth carries moral weight.

1. The Correspondence Theory (The Realist View)

Championed from Aristotle to Bertrand Russell and the early Ludwig Wittgenstein (in his 1921 Tractatus Logico-Philosophicus), Correspondence Theory holds that a proposition is true if and only if it corresponds to a real-world state of affairs.

The philosophical catch, however, is epistemological: human beings do not possess direct, unmediated access to raw physical reality. We perceive the world entirely through sensory organs and cognitive filtering. Because we cannot “step outside” our own consciousness to compare our mental representation of an object directly against the object itself, proving that our linguistic statements mirror objective reality with total certainty is notoriously difficult.

2. The Coherence Theory (The System View)

To bypass the problem of accessing “raw reality,” idealist philosophers like Baruch Spinoza, Georg Wilhelm Friedrich Hegel, and F.H. Bradley proposed an alternative: the Coherence Theory of Truth.

Here, truth is not about a statement matching an external physical world. Instead, a statement is true if it fits logically into a comprehensive web of existing beliefs without generating contradictions. We rely heavily on coherence in geometry, pure mathematics, and formal law, where a proof or verdict is judged “true” because it follows impeccably from established rules and axioms within that defined system. Internal consistency, however, does not guarantee factual reality; an elaborate conspiracy theory can be 100% internally coherent yet entirely false.

3. The Pragmatic Theory (The Epistemic View)

Developed by American philosophers Charles Sanders Peirce, William James, and John Dewey, the Pragmatic Theory of Truth ties truth directly to human action and experience.

An idea or theory is “true” insofar as believing it produces practical, useful results, allows us to make accurate predictions, or successfully guides our navigation of the environment. As William James put it, truth is the “cash value” of an idea. This aligns closely with modern science: we treat a physics model as “true” not because we can physically see invisible subatomic fields, but because the mathematical equations allow us to build microprocessors and land spacecraft on Mars.

4. Deflationism and Language Games (The Later Wittgenstein)

In the mid-20th century, thinkers like Gottlob Frege, Frank Ramsey, and most pivotally, the later Ludwig Wittgenstein, argued that two millennia of debate over “truth” rested on a fundamental grammatical misunderstanding. Deflationism asserts that “truth” is not a deep physical or metaphysical property at all.

While early Wittgenstein viewed language as a literal “picture” of reality, his Philosophical Investigations abandoned this, arguing that words derive meaning from their use within specific social activities, or Language Games. Under this view, adding “is true” to a sentence adds zero substantive content: saying “It is true that snow is white” means the exact same thing as “Snow is white.” Deflationists view “truth” merely as a grammatical shortcut to endorse claims efficiently.

When Language Games Collide: The Return of the Sophists

Laying out these four traditional theories assumes everyone is participating in a shared language game governed by rules that value empirical facts, logical consistency, practical utility, or linguistic clarity.

Toward the end of his life, in On Certainty, Wittgenstein pondered what happens when two people operate on completely incompatible language games. When fundamental premises conflict, reasoned argument eventually runs out. At that point, Wittgenstein noted, people stop offering reasons and resort to persuasion—attempting to convert the other person to their picture of the world.

This brings us to a crucial question: what happens when someone abandons the search for objective, shared criteria altogether?

In an online forum debate recently, a commenter stated their worldview with startling candor:

“I think that truth is whatever I can get people to believe.”

Philosophically, this commenter was not proposing a fifth alethic theory. Sophism is not a theory of truth. It does not define what makes a proposition true in a metaphysical sense. Instead, it is an epistemic stance that rejects the premise that objective truth matters for human life.

This idea dates back 2,500 years to the Sophists of Ancient Greece, most notably Protagoras (“Man is the measure of all things”). The Sophists were teachers of rhetoric in democratic Athens who argued that objective reality was unknowable or irrelevant. What mattered in the assembly or courtroom was not “what actually happened,” but who possessed the persuasive power to sway the jury. Socrates and Plato fought furiously against the Sophists, recognizing that reducing truth to sheer persuasion destroys the foundational pillars of ethics, justice, and societal trust.

The Fatal Shift: From Theory to Power

The shift from formal philosophy to Sophism fundamentally changes the question being asked in public life:

• Formal Alethic Theories: Ask “What corresponds to reality?”
  • Focus: Evidence, physical facts, and logical coherence.
  • Definition of Error: Making a factual or logical mistake about the physical world.
• The Sophistic Stance: Asks “What can I get you to believe?”
  • Focus: Power, rhetoric, and audience consensus.
  • Definition of Error: Suffering a tactical failure in strategy or losing the crowd.

The Destruction of “Error”

When someone adopts the Sophistic stance that truth is merely whatever you can convince others to accept, it completely eliminates the concept of being wrong.

Under Correspondence, Coherence, or Pragmatism, you are wrong if your claim fails against empirical evidence, internal logic, or practical outcomes. Under Sophism, “being wrong” simply means a tactical failure of strategy. In this worldview, an invented story that successfully convinces ten million people becomes “truer” in practice than an unvarnished, empirically verified fact that is poorly communicated. The lie achieved its objective; the fact failed to capture the room.

The Modern Dilemma: Alternative Facts and Memetic Reality

This ancient tension between philosophy and Sophism explains precisely why contemporary public discourse feels so surreal and exhausting.

When public figures introduce phrases like “alternative facts,” or when political commentators assert wildly unevidenced claims—such as viral stories regarding immigrants eating local pets in Ohio—they are not operating within the Correspondence Theory. They offer no verified data, police reports, or empirical documentation. Yet, millions of people treat those stories as if they carry immense, physical weight.

Modern political communication has largely migrated out of classical epistemology and back into Sophistic Rhetoric, operating on three principles:

1. Exploiting the Default: The general public operates naturally on the Correspondence Theory. They assume that when a public figure speaks with absolute confidence, real-world evidence must exist. Sophistic actors exploit this public faith without providing evidence.
2. Pragmatic Persuasion: Politically, a narrative is judged by whether it works. If a vivid story unifies a base, raises funds, drives media coverage, and turns out voters, strategists view it as functionally successful. Accuracy regarding physical reality becomes secondary to shaping behavior.
3. Cognitive Repetition: Social media amplifies this through the Illusory Truth Effect. When a meme or narrative is repeated thousands of times across feeds, the brain mistakes processing familiarity (cognitive fluency) for factual truth. Repetition replaces proof.

A Matter of Domain: Alethic Pluralism

Perhaps the ultimate challenge in understanding truth is recognizing that different human domains naturally demand different definitions. In contemporary philosophy, this perspective is known as Alethic Pluralism—the idea that truth is not a monolithic, one-size-fits-all property, but rather a concept that manifests differently depending on the context.

In physical science, structural engineering, and medicine, we cannot afford to abandon the Correspondence Theory. A bridge holds weight or collapses based on immutable physical laws, regardless of persuasive rhetoric. In formal logic, computer programming, and pure mathematics, Coherence remains supreme; a system functions only when its underlying rules maintain absolute internal consistency. In tool-making and empirical modeling, Pragmatism guides our progress by measuring what yields reliable outcomes.

The breakdown in modern public life occurs when these boundaries blur—when the mechanisms of pure Sophistic persuasion invade domains that depend entirely on empirical correspondence. Understanding how these frameworks operate does not solve the friction, but it reveals the true nature of our public disagreements: often, we are not simply arguing over the facts, but over which definition of “truth” we are using to judge them.

Suggested Reading

For readers interested in digging deeper into the philosophy of truth, epistemology, and language, the following texts offer essential foundational insights:

• Ludwig Wittgenstein, Philosophical Investigations (1953)Key Focus: The shift from language as a picture of reality to language as social “use” and “language games.”
• Ludwig Wittgenstein, On Certainty (1969)Key Focus: An examination of foundational beliefs, doubt, and what happens when competing worldviews clash beyond logical argument.
• William James, Pragmatism: A New Name for Some Old Ways of Thinking (1907)Key Focus: The classic exposition of the Pragmatic Theory of Truth, defining truth through practical, experiential outcomes.
• Plato, Gorgias and PhaedrusKey Focus: Socratic dialogues examining the fierce ancient battle between philosophy (the pursuit of objective truth) and rhetoric/Sophism (the art of persuasion).
• Michael P. Lynch, Truth as One and Many (2009)Key Focus: A modern, thorough defense of Alethic Pluralism, arguing how truth can function differently across science, ethics, and mathematics.
• Richard Rorty, Philosophy and the Mirror of Nature (1979)Key Focus: A major 20th-century critique of the Correspondence Theory, arguing that philosophy should abandon the idea of the mind as a “mirror” of reality.

In an era dominated by knee-jerk polarization and online echo chambers, public discourse often feels like a zero-sum war of attrition. Nowhere does this seem more pronounced than in debates over life’s ultimate questions: Does God exist? Are human beings biological machines, or created spirits? Is the cosmos governed by blind physical laws, or directed by divine purpose?

Yet, within academic philosophy, a remarkably different dynamic has quietly persisted. Over the past several decades, some of the world’s most brilliant thinkers—holding diametrically opposed worldviews—have engaged not in mudslinging, but in rigorous, mutually respectful, and surprisingly affectionate dialogue.

A premier example of this intellectual hospitality is the long-standing interaction among Alvin Plantinga (a traditional Christian theist), Daniel Dennett (a famous “New Atheist” and physicalist), and Thomas Nagel (a prominent secular atheist). Rather than treating each other as existential enemies, these three heavyweights demonstrated how deep philosophical disagreement can foster rich intellectual progress and mutual admiration.

The Metaphysical Spectrum

To appreciate their dialogue, one must first understand how radically their fundamental worldviews diverged:

• Alvin Plantinga (Christian Theism): Former professor at Notre Dame, Plantinga is widely regarded as one of the greatest living Christian philosophers. He argues that human reason, objective moral values, and scientific inquiry are coherent only if the universe was created by an intelligent, truth-loving God who designed our minds to track reality.
• Daniel Dennett (Physicalist Atheism): The late Tufts University philosopher was one of the “Four Horsemen” of modern atheism. Dennett maintained a strict materialist mandate: everything—including human consciousness, reason, and moral values—is entirely reducible to unguided physical processes, neurochemistry, and Darwinian natural selection.
• Thomas Nagel (Secular Non-Theism): The long-time NYU philosopher occupies a fascinating middle path. Nagel is an atheist who famously admitted to having a “fear of religion” and a hope that God does not exist. Yet, he is equally famous for arguing that materialist physicalism is utterly incapable of explaining consciousness, reason, and objective value.

Plantinga vs. Dennett: Sharp Debate, Deep Camaraderie

Given their polar-opposite positions, one might expect exchanges between Alvin Plantinga and Daniel Dennett to devolve into vitriol. Instead, their public debates were characterized by humor, genuine friendship, and razor-sharp argumentation.

The apex of their collaboration was born out of a live, high-profile debate held at the 2009 American Philosophical Association (APA) Central Division conference. Rather than leaving the exchange on the stage, the two philosophers directly collaborated with Oxford University Press to expand their written dialogue into the 2011 co-authored book, Science and Religion: Are They Compatible?

The book was structured not as a third-party commentary, but as a direct, back-and-forth written duel between the two thinkers:

1. Plantinga’s Opening Argument: Plantinga lays out his written case for why philosophical naturalism and science are incompatible, focusing heavily on his Evolutionary Argument Against Naturalism (EAAN).
2. Dennett’s Rebuttal: Dennett writes a direct point-by-point rebuttal attacking Plantinga’s premises.
3. Plantinga’s Reply: Plantinga responds directly to Dennett’s critique to clarify and defend his position.
4. Dennett’s Final Counter-Reply: Dennett offers his closing written pushback to conclude the volume.

In the book’s main dispute over the EAAN, Plantinga argues that combining philosophical naturalism (the belief that no God exists) with evolutionary theory is logically self-defeating. He points out that natural selection filters strictly for adaptive survival behaviors—what he calls the “4 Fs” (feeding, fleeing, fighting, and reproducing)—completely ignoring whether the internal mental beliefs driving those actions are factually true. Because infinitely many false beliefs can produce survival-enhancing behaviors, Plantinga argues that if our minds are the product of unguided natural selection, the probability that our cognitive faculties produce true beliefs is low or unknowable. Thus, the naturalist acquires a “defeater” for trusting their own mind—including their belief in naturalism itself.

Dennett fought back with classic intellectual vigor. He argued that Plantinga artificially divorced behavior from truth. In Dennett’s view, navigating a complex, dangerous physical world requires an organism to maintain an accurate internal map of reality. Tracking the truth inherently carries immense survival value; therefore, natural selection directly favors cognitive engines calibrated for accuracy. Pushing back against Plantinga’s theistic alternative, Dennett famously asserted that theism was a “failure of imagination” and compared belief in God to “Supermanism”—the absurd claim that comic book heroes seeded life—arguing that mere logical consistency with science does not make a claim reasonable.

While neither convinced the other to abandon their core worldview, their co-authored book stands as a masterclass in philosophical debate: challenging premises aggressively while treating the opponent with warmth and respect.

Nagel and Plantinga: The Atheist Who Defended a Theist

Perhaps the most surprising alliance in modern philosophy occurred between Thomas Nagel and Alvin Plantinga.

When Plantinga formulated his EAAN critique of materialist evolution, Nagel took notice. In his widely debated 2012 book, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False, Nagel did something almost unheard of for a prominent secular philosopher: he openly defended the validity of Plantinga’s anti-materialist arguments.

Nagel agreed with Plantinga that if human minds were assembled purely by unguided material collisions and survival selection, we would have no rational basis for trusting our capacity to discover abstract logic, higher mathematics, or objective moral truths. In ethical theory, this aligns with the “Darwinian Dilemma” posed by Sharon Street, who noted that natural selection shapes evaluative attitudes toward evolutionary fitness rather than metaphysical truth. While Street used this dilemma to reject moral realism in favor of constructivism, Nagel flipped the argument on its head: because objective reason and moral values are an undeniable datum of human experience, it is materialist physicalism—not moral realism—that must be incomplete or false.

However, because Nagel rejected theism, he refused Plantinga’s solution (that God calibrated human minds). Instead, Nagel proposed a secular alternative: Natural Teleology. Nagel hypothesized that the universe is governed not only by mechanical physical laws, but also by non-physical, secular laws of direction built into nature itself—inclining the cosmos toward the realization of mind, consciousness, and value over time.

Plantinga, in turn, reviewed Nagel’s work with great respect, appreciating that a secular thinker was willing to follow the evidence against materialist dogma, even if they disagreed on the ultimate destination.

The Wider Metaphysical Debate: Mechanics, Reductionism, and Meaning

This exchange highlights how the debate over human consciousness branches into very different models of reality:

1. The Mechanics of the Brain vs. The Reality of Subjective Experience

Dennett’s functional materialism views the mind through the lens of evolutionary algorithms. He argues that human consciousness is a “User Illusion”—a narrative software running on trillions of mindless biological “tiny robots” (cells and neurons) through competence without comprehension. For Dennett, our subjective feeling of an irreducible soul is simply a functional trick engineered by natural selection to help the organism navigate social and physical environments.

2. The Limits of Scientific Reductionism

Opponents of strict materialism—including both theists like Plantinga and secular anti-reductionists like Nagel or neuroscientist Raymond Tallis—argue that reductionism fails to bridge the “explanatory gap”. Tallis argues against “Neuromania” and “Darwinitis,” pointing out that a physical system of unthinking cells cannot account for the intentionality, unity, and “aboutness” of human thought. While Dennett sees the brain as an isolated organic computer running software, thinkers influenced by the Extended Mind Thesis (such as Andy Clark and David Chalmers) propose a middle ground: the brain may be a machine, but human consciousness extends out into an interconnected web of culture, tools, and shared human language.

Lessons for a Polarized World

The ongoing dialogue among Plantinga, Dennett, and Nagel offers several vital lessons for how we engage across ideological divides:

• Acknowledging Valid Points Across the Aisle: Nagel demonstrated immense intellectual courage by acknowledging that a Christian philosopher had delivered a devastating critique of materialist science. He did not allow tribal loyalty to blind him to a strong argument.
• Separating Arguments from Ad Hominem: Dennett and Plantinga demonstrated that one can hold radically different views on the origin of life and the existence of God without viewing the opponent as foolish, malicious, or dishonest. They fought the ideas, not the person.
• The Pursuit of Truth Requires Hospitality: Real philosophical progress happens when thinkers grant their opponents the strongest possible interpretation of their arguments.

True intellectual rigor does not demand that we abandon our core convictions or pretend that fundamental disagreements do not exist. Rather, as Plantinga, Dennett, and Nagel have shown, it demands that we treat our philosophical opponents not as enemies to be defeated, but as essential partners in the shared human quest to understand reality.

Suggested Reading

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• Dennett, Daniel C. & Plantinga, Alvin. Science and Religion: Are They Compatible? Oxford University Press, 2011.
  The definitive co-authored text capturing their 2009 APA debate and written exchanges on naturalism, evolution, and cognitive reliability.
• Nagel, Thomas. Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False. Oxford University Press, 2012.
  Nagel’s controversial critique of reductive physicalism and defense of natural teleology.
• Plantinga, Alvin. Where the Conflict Really Lies: Science, Religion, and Naturalism. Oxford University Press, 2011.
  Plantinga’s comprehensive defense of the compatibility between Christian theism and modern science.
• Street, Sharon. “A Darwinian Dilemma for Realist Theories of Value.“ Philosophical Studies, 2006.
  The seminal paper outlining the evolutionary debunking argument that sparked the moral realism debate.
• Tallis, Raymond. Aping Mankind: Neuromania, Darwinitis and the Misrepresentation of Humanity. Acumen, 2011.
  A physician-philosopher’s critique of reducing human culture and consciousness to evolutionary biology.