Can You Define Knowledge? A 12th‑Century Philosopher Said No
The Shell Game: Why True Belief Isn’t Enough
Imagine a gambler in ancient India. A bookie shakes a fistful of shells and asks, “How many?” The gambler hasn’t seen inside, but a hunch whispers “Five.” The bookie opens his hand: five shells. The gambler got it right. But did he know there were five? Most people say no—getting something right by pure luck isn’t knowledge.
This is the kind of puzzle that a 12th‑century Indian philosopher, Śrīharṣa (12th century CE), used to attack a whole way of thinking about knowledge, reality, and reason. His target was the Nyāya school, a tradition that had spent centuries trying to define everything precisely. Nyāya philosophers believed that if you could lay down a correct definition—a set of necessary and sufficient conditions for something—then you could distinguish real things from false appearances and guide your inquiry toward the truth.
Śrīharṣa set out to show that every attempt to define basic concepts like knowledge, causation, or even difference crumbles under pressure. He didn’t just nitpick; he argued that the very tools the Nyāya philosophers used to build their system—clear definitions—could never be built in the first place. If he was right, the project of rational inquiry itself might be a dead end.
The Rules of the Definition Game
Before launching his attacks, Śrīharṣa accepted three rules for what makes a definition good—rules his Nyāya opponents also endorsed. First, a definition must be extensionally adequate: it should fit all and only the things it’s supposed to pick out. It can’t be too narrow (missing some genuine cases) or too wide (including things that don’t belong). Second, it must be non‑circular: you can’t define a word by sneaking that same word, or a close cousin, back into the explanation. Third, it must be uniform: a single definition should capture a single property that all instances share, not a messy disjunction like “knowledge is either this, or that, or something else.”
These three rules became both the battlefield and the weapons. Śrīharṣa’s strategy was to accept the rules and then show that no definition of a key concept could satisfy all of them at once. If he succeeded, the Nyāya philosopher couldn’t even specify what she was talking about. And if you can’t distinguish a causal condition from a mere coincidence, or genuine knowledge from a lucky guess, then the whole Nyāya project of mapping reality falls apart.
Can We Build a Better Definition of Knowledge?
The gambler’s lucky guess shows that true belief alone isn’t knowledge—philosophers today call this a case of epistemic luck. Śrīharṣa described similar examples: a traveller mistakes mist for smoke and infers there’s a fire; by coincidence, there really is a fire, but the traveller doesn’t know. Or someone spots horns on an animal, wrongly assumes only cows have horns, and concludes “That’s a cow.” It is a cow, but the guess was based on a bad reason. In all these cases, the belief is true but too lucky to count as knowledge.
So maybe knowledge requires a reliable method. Nyāya philosophers proposed that knowledge is true awareness produced by a method that never leads to false awareness. Śrīharṣa spotted a problem. If an awareness‑episode is true, the Nyāya thinkers themselves held that the causal conditions that produced it must be good enough to guarantee truth. But if that’s so, then any true non‑recollective awareness would be produced by a method that never fails—including the gambler’s lucky guess. The definition would fail to rule out luck.
Another version defined knowledge as awareness produced by a non‑defective method. But what is “defective”? If “defective” just means “likely to produce false awareness,” the definition becomes circular: we’re defining knowledge in terms of a method’s defectiveness, which itself is defined in terms of false awareness—and false awareness is just awareness that isn’t knowledge.
Śrīharṣa also considered the idea that knowledge involves discrimination—being aware of a distinctive mark that sets the object apart from similar things. That rules out the horn case nicely. But the relevant distinctive mark changes from case to case (earth has smell, cows have dewlaps), so the definition can’t be uniform. Worse, in a scenario Śrīharṣa calls Castor and Pollux, two people hear identical testimony about five fruits on a tree; one is talking to a reliable speaker, the other to a liar. Both awareness‑episodes feel the same inside, yet only one counts as knowledge. No distinctive mark seems to be present in the knower’s mind that isn’t in the other’s. The discrimination theory can’t explain the difference.
At this point some might say: maybe knowledge is a basic, unanalyzable property—knowledgehood—and we just recognize it. Śrīharṣa pushed back. If knowledgehood is a real property, we’d need some way to detect it. But we can’t introspect knowledgehood directly (I can be aware of a thought without being sure it’s knowledge), so we’d have to infer it from some symptom. Without a non‑circular definition, we have no reliable symptom. The idea that knowledge is a primitive property leaves us unable to explain how we ever identify knowledge at all.
Causation: The Domino That Won’t Fall
Nyāya thinkers also wanted to define what it means for one thing to be a causal condition for another. A common proposal was invariable conjunction: a condition c is a cause of effect e if c always comes right before e. But Śrīharṣa showed this catches too much. The early symptoms of a disease always appear before the later symptoms, because they share a common cause, yet we don’t say the early symptoms cause the later ones. This is the problem of spurious correlations. Adding a requirement of necessity doesn’t fix it either: a thread’s colour is necessarily present before a cloth is woven, but colour isn’t a cause—the thread itself is.
Later Nyāya philosophers added a condition of non‑superfluity: a genuine cause is not “established otherwise,” independent of the effect. Śrīharṣa tore this apart. Does “established” mean “brought into existence”? A cause isn’t brought into existence by its own effect. Does it mean “cognized”? We sometimes understand causes without knowing their effects, like spotting rain‑clouds directly. The only way to make non‑superfluity work is to say a condition is non‑superfluous if it is established as a cause for the effect—but that’s circular.
Even the powerful argument that occasional things (things that pop up sometimes, not always) need a cause came under fire. Śrīharṣa argued that explaining the occasionality of an effect by appealing to a separate cause violates a principle of explanation: a property of one thing should be explained by properties of that same thing, not by something entirely different. If you try to explain the occasionality of a cause itself, you either launch an infinite regress or have to show at least one non‑circular case where the link holds—and that, he claimed, nobody had done.
The Puzzle of Distinctness: When Difference Vanishes
Ultimately, Śrīharṣa wanted to defend non‑dualism—the Advaita Vedānta view that only consciousness is ultimately real and that the world of many separate objects is an appearance. To make that plausible, he attacked the very notion of distinctness. Is the difference between a pot and a cloth something real? Śrīharṣa examined four possibilities.
If distinctness is just the nature of the object itself, then for the pot to be distinct from the cloth, the cloth’s nature must somehow be part of the pot’s nature (since being distinct from a cloth is a relational property that involves the cloth). By similar reasoning, the pot’s nature would be part of the cloth’s nature. That makes pot and cloth identical—the opposite of distinct.
If distinctness is mutual absence (a pot just is the absence of being‑identical‑to‑a‑cloth), then for that absence to be real, what it is an absence of—the pot’s identity with the cloth—must also be real. Again, identity creeps back in.
If distinctness is difference in properties, then we must ask what makes the properties themselves distinct. If we say they have further distinguishing properties, we start an endless regress. If we stop the regress by admitting that some properties aren’t really distinct, then the original pot and cloth also turn out not to be really distinct.
No matter which path you take, Śrīharṣa claims that any awareness that tries to present two things as different also, when pushed, reveals them as identical. If he’s right, ordinary perception can’t contradict the non‑dualist scripture that says everything is ultimately one.
Consciousness: The One Thing That Shines by Itself
While Śrīharṣa thought the world of objects can’t be defined, he didn’t doubt consciousness. In fact, he argued that conscious mental occurrences are self‑intimating: each one makes itself known without needing anything else. If you have a pain, a thought, or a visual experience, you can’t be wrong about the fact that you are having it. You might be wrong about what caused it, but not that it’s there.
A rival view said we need a separate higher‑order awareness—a second mental act that notices the first. Śrīharṣa replied that if that were true, you’d need a third act to notice the second, and so on ad infinitum. If the chain stops somewhere, you could doubt the last link’s existence, and that doubt would infect all the earlier ones, making you unsure even of your own present experience. Since rational action requires certainty about your own awareness (otherwise you couldn’t rely on it to guide your behaviour), Śrīharṣa concluded that conscious episodes just are aware of themselves, as part of their very nature.
He also tackled the aboutness relation—how an awareness can be of an object. Some Nyāya philosophers said this relation is just the awareness’s own special nature, a “being‑of‑that‑ness.” Śrīharṣa argued that if the object is part of the awareness’s nature, then the object isn’t external to the awareness—the view collapses into idealism, where everything is mind. That, for an Advaita thinker, isn’t a bug but a feature: the only thing left standing is consciousness itself.
Why Inquiry Hits a Wall: Faith and the Limits of Reason
So where does all this leave us? Śrīharṣa’s conclusion is startling. He argues that rational inquiry—the kind the Nyāya school thought was the highest good—is actually futile. Even asking the question “How do we know non‑duality?” runs into a paradox. If you don’t already have some idea of non‑duality, you can’t even form the question, because your speech act would need to be about something you know nothing about. If you do have an awareness of non‑duality, but it isn’t knowledge, then there’s no method that turns it into knowledge—you’re stuck. The only way out, he suggests, is to abandon the idea that reason alone can get us to truth.
For Śrīharṣa, the right response is not to keep arguing but to have faith (śraddhā) in the sacred Upaniṣadic texts that proclaim everything is one with consciousness. He argues that reason is always unstable: any clever argument can be met by an even cleverer counter‑argument. He compares relying solely on reason to a blind person groping along a rocky path, bound to stumble. Only by first trusting scripture, and then letting that trust settle the mind, can someone come to see the truth directly.
This idea—that reason has limits and that some truths are better approached through trust or personal transformation—still echoes today. Not just in religious traditions, but in the recognition that even our best scientific theories rest on unprovable starting points, or that endless debate on the internet rarely changes anyone’s mind.
Think about it
- If you can’t give a perfect definition of “knowing,” does that mean no one ever really knows anything? How would you decide in everyday life?
- Śrīharṣa thought the very idea of difference might be an illusion. Can you think of two things that are clearly different, but you’d struggle to explain exactly what makes them different? What does that tell you?
- Some people say you should trust your gut even when you can’t prove things with logic. Śrīharṣa said faith in scripture is the only guide. Do you think there are times when reason should be set aside? Give an example.
