What Is Truth?

Why Truth Matters More than Ever

*Post tenebras lux:* After darkness, light.

Article substantially revised on 26 July 2026.

Veritas vos liberabit: The truth shall set you free. —John 8:32

Truth has always mattered. But never before have we had access to so much information—or misinformation. Our ability to distinguish truth from falsehood has become one of the defining challenges of modern life.

Truth tends to lead to successful action. In that much, truth has instrumental value. But truth also has intrinsic value. Given the choice between a life of limitless pleasure as a brain in a vat and a genuine human life, along with all its pain and suffering, most people opt for the latter.

In Plato’s Cratylus, on the philosophy of language, Socrates says that aletheia (Greek, ‘truth’) is a compression of the phrase ‘a wandering that is divine’. Since Plato, many thinkers have spoken of truth and God in the same breath, and truth has also been linked with concepts such as justice, power, and freedom. According to John the Apostle, Jesus said to the Jews: ‘And ye shall know the truth, and the truth shall set you free.’

Fake News and Lies

Following his defeat at the Battle of Actium in 31 BC, Mark Antony heard a rumour that Cleopatra had committed suicide and, in consequence, stabbed himself in the abdomen—only to discover that Cleopatra herself had been responsible for spreading the rumour. He later died in her arms. Fake news is nothing new, but in the internet age it spreads faster than ever, swinging elections, fomenting social unrest, undermining institutions, and diverting political capital away from health, education, and good government.

Those who are alarmed, or who despair, might take some comfort in the words of Søren Kierkegaard:

Truth always rests with the minority, and the minority is always stronger than the majority, because the minority is generally formed by those who really have an opinion, while the strength of a majority is illusory, formed by the gangs who have no opinion—and who, therefore, in the next instant (when it is evident that the minority is the stronger) assume its opinion… while truth again reverts to a new minority.

One way to understand truth is to consider its opposites, namely, lies and bullsh*t. Lies differ from bullsh*t in that the liar must track the truth in order to conceal it, whereas the bullsh*tter has no regard or sensitivity for the truth or even for what their audience believes.

In the words of Harry Frankfurt:

Someone who lies and someone who tells the truth are playing on opposite sides, so to speak, in the same game. Each responds to the facts as he understands them, although the response of the one is guided by the authority of the truth, while the response of the other defies that authority and refuses to meet its demands. The bullsh*tter ignores these demands altogether. He does not reject the authority of the truth, as the liar does, and oppose himself to it. He pays no attention to it at all. By virtue of this, bullsh*t is a greater enemy of the truth than lies are. —On Bullshit

The Correspondence Theory of Truth

Let’s now turn to the three most influential positive theories of truth, starting with the correspondence theory. We shall then consider two important challenges to these traditional accounts.

For centuries, philosophers have agreed that thought or language is true if it corresponds to an independent reality. For Aristotle, ‘to say that what is is, and what is not is not, is true.’ For Avicenna, truth is ‘what corresponds in the mind to what is outside it.’ And for Aquinas, it is ‘the adequation of things and the intellect’ (adæquatio rei et intellectus).

Unfortunately for this so-called correspondence theory of truth, the mind does not perceive reality as it is, but only as it can, filtering, distorting, and interpreting it. In modern times, it has been argued that truth is constructed by social and cultural processes, to say nothing of individual desires and dispositions. Michel Foucault famously spoke, not of truth or truths, but of ‘regimes of truth.’ Categories and constructs concerning, for example, race, sexuality, and mental disorder may not reflect biological let alone metaphysical realities.

The Coherence Theory

Some philosophers have therefore argued that truth lies not in correspondence with an independent reality but in coherence within a system of beliefs.

On this view, a belief is true if it fits consistently with everything else we have good reason to believe. Truth, then, is less a matter of matching reality than of belonging to a coherent web of beliefs, each supporting and being supported by the others. Scientific theories, for example, are valued not only because they explain observations but because they integrate them into a coherent whole.

The coherence theory has particular appeal where direct verification is impossible. A new discovery is convincing not simply because it explains one fact, but because it fits with many others without creating contradictions.

But coherence alone cannot guarantee truth. A detective novel may be internally consistent while remaining entirely fictional. A system of beliefs can be perfectly coherent without corresponding to reality. Coherence is valuable, but coherence alone is not enough.

The Pragmatic Theory

Pragmatist philosophers such as William James proposed a different approach. Rather than asking whether a belief corresponds to reality or coheres with other beliefs, they asked whether it works.

A belief is true, they argued, insofar as it proves reliable in experience and enables us to navigate the world successfully. Scientific theories, for instance, are continually tested by their practical consequences. We could scarcely have sent astronauts to the Moon if our science had been wide off the mark. If something works, it may well be true; if it does not, it probably is not.

This emphasis on practical success reflects an important feature of truth. Our beliefs matter because they guide our actions. False beliefs eventually collide with reality.

Yet usefulness is not always the same as truth. What if something works for me but not for you? Is it then true for me but not for you? Some comforting illusions may help people cope with adversity without thereby becoming true. Conversely, some painful truths may offer no immediate practical benefit while remaining true nonetheless.

The Deflationary Theory

That a thing fits into a system, or leads to successful action, may suggest that it is true, but does not tell us much about what truth actually is, while the correspondence theory of truth is so thin as to be almost or entirely tautological. And perhaps for a reason. According to the deflationary or redundancy theory of truth, to say that ‘X is true’ is merely to say that X, and therefore that truth is an empty predicate. Truth is not a real property of things. Rather, it is a feature of language used to emphasize, agree, or hypothesize, or for stylistic purposes. For example, it can be used to explicate the Catholic dogma of papal infallibility: ‘Everything that the pope says is true.’ But this is merely shorthand for saying that if the Pope says A, then it is the case that A; and if he says B, then B.

The Verification Theory

For some thinkers, something can only be true or false if it is open to verification, at least in theory if not also in practice. According to the verification theory of truth, the truth of something lies at the end of our inquiry into that thing. Every observation, experiment, and argument brings us a little closer to the truth, even if we can never be certain that we have reached it.

But as our inquiry can have no end, the truth of something can never be more than our best opinion of that thing. If best opinion is all that we can have or hope for, then best opinion is as good as truth, and truth is a redundant concept.

But best opinion is only best because, at least on average, it is closest to the truth, which, as well as instrumental value, has deep intrinsic value.

The Real Barrier

The ancient Greeks pictured truth as something elusive. In the Odyssey, Menelaus seeks out the sea-god Proteus because only Proteus knows the fate of the Greek heroes. But before he will reveal the truth, Proteus repeatedly changes shape, becoming a lion, a serpent, a boar, even running water. Only when Menelaus refuses to let go does the sea-god resume his true shape and answer his questions. Truth, Homer suggests, does not simply present itself. It must be patiently pursued through appearances that are shifting, deceptive, and often frightening.

In any case, the greatest challenge to truth may not come from epistemology or metaphysics but from ourselves.

Human beings are not impartial observers. Our perceptions are shaped by expectations, emotions, loyalties, and unconscious motives. We readily notice evidence that confirms what we already believe while overlooking evidence that challenges it. We are often less interested in discovering the truth than in protecting our identities, reputations, and worldviews.

For this reason, the pursuit of truth requires intellectual virtues as much as intellectual abilities. Curiosity, humility, honesty, and the willingness to change one’s mind may matter at least as much as intelligence.