2. What is Knowledge? | Quomodo Scimus : IBTOK

The Core Theme - Knowledge and the Knower

Lesson 2 - What is Knowledge? (Scope 2)

Everyone assumes they know what knowledge is. Philosophers have spent 2,500 years discovering that the answer is far harder than it looks.

You have just spent twelve or more years in school, accumulating what everyone around you called “knowledge.” But what exactly were you accumulating? Is knowing a fact the same as knowing how to do something? Is knowing something the same as believing it very strongly? These questions are not word games, they are all about what education is for, and what the IB TOK course is asking you to think about.

THE PROVOCATION

Two schools, two ideas of knowledge

Is knowledge something you accumulate, or something you do? The answer shapes everything about how a school teaches you.

"To stress process at the expense of factual knowledge actually hinders children from learning to learn."

E.D. Hirsch, "You can always look it up... or can you?" (2000)

There is a debate in education right now, one you may have experienced without knowing it had a name. On one side: the knowledge-rich curriculum and on the other side: the skills-based curriculum.

The knowledge rich argument for education is that students cannot think critically, analyse, or reason effectively without a rich store of factual knowledge in memory. Skills rest on knowledge. You cannot evaluate an argument about the French Revolution if you do not know what the French Revolution was. You cannot read critically if your vocabulary is thin. I made a short film about this a few years ago.

The skills-based education argument is that in a world of instant information access, what matters is not what you know but what you can do with information. Memorising facts is the wrong goal. Teach students to search, evaluate, synthesise, create. The skill of critical thinking transfers across contexts. Knowledge, in this view, is what you look up, not what you carry.

You are sitting in the middle of this debate. The Swiss Maturité leans toward the knowledge-rich tradition: lots of content, sustained study of traditional texts and methods, high expectations of factual recall. The IB leans toward the skills-based tradition: approaches to learning (ATLs), self-directed inquiry, transferable competencies. The fact that you have experienced both gives you something most people in this debate do not have: an insider’s perspective.

But before we can decide who wins that debate, we have to answer a more basic question: What is knowledge? Not what does it feel like, not what do schools call it, but what actually makes something knowledge rather than mere belief, opinion, or information? That is the question TOK is built around. And philosophers have been arguing about it for 2,500 years.

Traditional vs Progressive Education
Seah Seng Wee and NotebookLM.

This video generated with the help of AI outlines the key features of traditional and progressive education and concludes with an argument that is best to do both if you can!

Four big ideas about the nature of knowledge.

Big idea 1 - The classic answer: Justified True Belief

What would make a belief something more than a belief? What would make it knowledge?

"True opinions are a fine thing and do all sorts of good so long as they stay in their place; but they will not stay long. They run away from a man’s mind, so they are not worth much until you tether them by working out the reason." - Plato, Meno, trans. G.M.A. Grube.

Philosophy’s standard answer to “What is knowledge?” was, for most of its history, both elegant and compelling. Knowledge, the tradition held, is belief that is true, and that you have good reason to hold. In the language philosophers use: knowledge is Justified True Belief, or JTB. The three conditions are each necessary, and together they were thought to be sufficient.

Belief: you must actually hold the proposition, you cannot know something you have never considered.
Truth: the proposition must correspond to reality, you cannot know something false.
Justification: you must have adequate grounds for your belief, a lucky guess, even if correct, does not count as knowledge.

Consider two situations. In the first, you watch Wales beat France in the rugby Six Nations. You believe Wales won, your belief is true, and you have a reliable basis for it - you saw it happen. JTB says you know Wales won. In the second, you missed the match and a friend - someone who never watches rugby and was guessing - texts to say Wales won. They happen to be right. Your belief is still true. But the source is not reliable, and the fact that your friend guessed correctly this time was luck. JTB says you do not know Wales won - not because you had no reason for your belief, but because the reason was not the kind that connects beliefs to truth reliably. Justification, on this account, is not just any reason for believing something. It is a reason that is epistemically trustworthy - one that tends to produce true beliefs because it is tracking something real.

This framework traces back to Plato. In the Meno, Plato uses the image of statues of Daedalus that walk away unless you tie them down. True beliefs, he says, are like those statues: they are valuable only when fastened by reasoning. In the Theaetetus, Plato works through the problem more systematically, testing and eventually rejecting several candidate definitions of knowledge before arriving at something close to JTB. For roughly 2,400 years after Plato, Western philosophy treated JTB not as one possible answer but as the answer.

The philosophical vocabulary that comes with JTB matters beyond this lesson. Propositional knowledge, “knowing that” something is the case, is the territory JTB is designed to map. When you claim to know that the Battle of Hastings was in 1066, that climate change is human-caused, that Wales won the Six Nations in 2019: these are propositional knowledge claims, and JTB sets out what makes them genuine knowledge rather than mere belief. Keep that vocabulary, you will need it throughout the course.

JTB and Gettier
CrashCourse

In this cat rich episode Hank Green talks about some philosophy stuff, like a few of the key concepts philosophers use when discussing belief and knowledge: what defines an assertion and a proposition, and that belief is a kind of propositional attitude. Hank also discusses forms of justification and the traditional definition of knowledge, and introduces us to Edmund Gettier.

Big idea 2 - The crack in the foundation: Gettier

Can you have a justified true belief that is not knowledge?

"...it is possible for a person to be justified in believing a proposition that is in fact false"

Edmund Gettier, "Is Justified True Belief Knowledge?" (1963)

In 1963, a philosopher named Edmund Gettier published a paper three pages long. He was thirty-five years old and, by his own account, did not think it was much of an essay. He almost did not publish it. He submitted it mainly to have something on his CV. The paper was called "Is Justified True Belief Knowledge?" and it changed philosophy.

Gettier's method was simple: he constructed cases where all three conditions of JTB are met - belief, truth, justification - and yet something has clearly gone wrong. The subject does not seem to know anything. The cases are brief, almost conversational, but their implications for JTB were devastating.

Case One: The Job and the Coins

Smith and Jones have both applied for the same job. Smith has strong evidence - the company president told him directly - that Jones will get the job. Smith also knows that Jones has exactly ten coins in his pocket; he counted them himself ten minutes earlier. Smith therefore forms the justified belief: "The man who will get the job has ten coins in his pocket."

As it turns out, Smith gets the job, not Jones. And, by a coincidence Smith had no way of knowing about, Smith also has exactly ten coins in his own pocket. So the proposition "The man who will get the job has ten coins in his pocket" is true. Smith believed it. Smith was justified in believing it. But Smith did not know it - his belief was grounded in facts about Jones, and the proposition turned out to be true for reasons entirely unconnected to Jones.

Case Two: The Ford and Barcelona

Smith has strong evidence that his friend Jones owns a Ford. Jones has always driven a Ford, has just been seen driving one, and has offered Smith a lift in it. Smith therefore forms the justified belief: "Jones owns a Ford." He then constructs three further beliefs by logical addition, picking three city names at random: either Jones owns a Ford, or Brown is in Boston; either Jones owns a Ford, or Brown is in Barcelona; either Jones owns a Ford, or Brown is in Brest-Litovsk. Each is logically entailed by the first belief, so if "Jones owns a Ford" is justified, all three are too.

As it turns out, Jones does not own a Ford - he was driving a rental car. But Brown, completely by coincidence, really is in Barcelona. So "Either Jones owns a Ford or Brown is in Barcelona" is true. Smith believed it. Smith was justified in believing it. But Smith did not know it - the proposition is true for a reason Smith had no access to, and the belief is true entirely by accident.

Both cases share the same structure. Justification and truth are both present, but they come apart: the justification points in one direction, and the truth arrives from somewhere else. Gettier's conclusion is stark: JTB is not sufficient for knowledge. Something is missing. What that missing ingredient is has occupied epistemologists ever since.

In each case, the knowing is real, but it cannot be fully articulated. Polanyi illustrates this with the example of a tool. When a carpenter uses a hammer, they are not conscious of hammer, they 'know' it through it the nail that is hit. The tool has been incorporated into the knower’s body. The same is true of the concepts a scientist uses, or the grammar a fluent speaker employs. This knowledge disappears into the background, it is transparent, taken for granted. That background is where most of our knowledge lives. We looked at this idea in our Critical Thinking lessons in 11e as the difference between System 1 and System 2 and we will also revisit this in a future lesson. All this is important to how we view education and assessment. If much of the most significant knowledge is tacit, embodied in skill, judgment, and practice rather than in propositional or declarative knowledge*, then exams and essays capture only a fraction of what a knower actually knows. The question is not just “what do you know?” but “how much of what you know can you put into words on the exam page?” and whether the gap between the two matters.

* Propositional knowledge (“knowing that” — knowledge of facts, statements, or claims; e.g. knowing that the Earth orbits the Sun) Declarative knowledge (knowledge that can be stated or described in words; e.g. knowing the causes of the French Revolution or the formula for photosynthesis)

Big idea 3 - The map of knowledge

You are already multilingual. Your French already knows more about knowledge than English does.

"The man who has no tincture of philosophy goes through life imprisoned in the prejudices derived from common sense, from the habitual beliefs of his age or his nation, and from convictions which have grown up in his mind without the co-operation or consent of his deliberate reason." Bertrand Russell, The Problems of Philosophy

You have an advantage in this lesson that most anglophone TOK students do not have. You know that to translate "to know" in German you have Wissen and Kennen. And you might also know that Italian has sapere and conoscere and that Spanish has saber and conocer. Every major European language except English encodes, in its most basic vocabulary, a distinction that philosophers took centuries to articulate in analytical terms. If you have ever felt that something was lost in translation when you switched from French to English - that a sentence "knew" something in French that it could not quite say in English - this is often why. What English calls "knowing" turns out to cover very different things. That is what this section maps out.

Je connais, je sais et je suis.

In French, to know that Paris is in France and to know Paris are not the same verb. "Je sais que Paris est en France" - savoir: to know a fact, a proposition, something that can be stated and verified. "Je connais Paris" - connaître: to know a city, a person, a piece of music, by direct experience and acquaintance. Two different relationships with the world, two different verbs. English collapsed them into one word sometime in the medieval period, and anglophone epistemology has been trying to reconstruct the distinction ever since.

And then there is être. To be. The French philosophical tradition, from Descartes to Sartre, insists on a connection that the English language makes easier to ignore: knowing and being are not separate activities. Descartes' "Je pense, donc je suis" - I think, therefore I am - is not just a proof of existence. It is a claim that the act of knowing is itself a mode of being. To ask "What do I know?" already presupposes a conscious subject, located in a body, shaped by a history, embedded in a language. Knowing happens to and through a particular kind of being. Which is why Lesson 1, the Knower, had to come before this lesson.

The philosopher Bertrand Russell formalised the savoir/connaître distinction in English. He called it knowledge by acquaintance and knowledge by description. Knowledge by acquaintance is direct, immediate contact with something - the redness of a sunset as you actually see it, the taste of coffee as you drink it, the texture of a city you have lived in. No description can fully substitute for acquaintance. Knowledge by description is indirect: it is knowing that something has certain properties, often without direct experience of it. You can know, by description, that the tallest mountain on Earth is 8,849 metres high without ever having seen Everest. Your friend in Australia can know, by description, that Geneva is a typical Swiss city without travelling here. Russell's point: connaître tracks acquaintance; savoir tracks description. French had already done the philosophy.

A related distinction, rooted in the work of another English philosopher Gilbert Ryle, separates propositional knowledge ("knowing that") from procedural knowledge ("knowing how"). In The Concept of Mind (1949), Ryle argued that the Cartesian picture of a mind-ghost operating a mechanical body generates a systematic error: the assumption that all knowledge is ultimately a kind of inner knowing-that, a proposition held in the mind. But knowing how to ride a bicycle is not a set of propositions about balance and pedalling. Expert cyclists cannot articulate what they know. The knowledge lives in the body, in trained patterns of response. It is procedural rather than propositional. Listen to the story that comedy legend John Cleese has to tell.

This distinction also matters enormously for the education debate you were asked to think about at the start of this lesson. "Critical thinking" cannot be taught as a pure skill because there is no such thing as context-free critical thinking: it always requires propositional knowledge, knowledge of the domain you are thinking about. The skills advocate's response might be that procedural knowledge - the habit of mind, the practice of evaluation - genuinely transfers across domains in a way that propositional knowledge does not. Both sides of the debate need this vocabulary to be having the right argument.

A further distinction runs through both everyday language and philosophical argument: knowledge versus belief versus opinion versus information. These are not synonyms. Information is data, a raw signal that may or may not be true and that does not, on its own, constitute knowledge. Belief is any proposition you hold to be true, regardless of whether it is true or justified. Opinion is usually a belief about a contested matter where the grounds are disputed. Knowledge, on the Justified True Belief account, requires all three conditions. Keeping these distinctions clear is the basic equipment for thinking carefully about what you know and how you know it.

Big Idea 4 - What is knowledge for?

Once we know what knowledge is, we have to ask: why does it matter?

"We are now a culture whose information, ideas and epistemology are given form by television, not by the printed word." Neil Postman, Amusing Ourselves to Death

The Gettier problem showed that knowledge is harder to define than anyone thought. The forms of knowledge showed that it is more varied than a single definition can capture. A fourth question remains - one that education forces us to ask, and that TOK exists to answer: what is knowledge actually for?

The American media theorist Neil Postman spent much of his career documenting what happens when a culture becomes so saturated with information that the question of what it is for disappears entirely. In Technopoly (1992), he described a society that had surrendered to technology, in which information had become its own justification - circulated and consumed without any governing framework for asking whether it was useful, true, or good. He wrote that book the same year I first entered the classroom as a teacher. It was already true then, and that was before the internet, social media and AI. There was genuine optimism in education in the 1990s about the possibilities of a world where everyone might have instant access to what Matthew Arnold called "the best that has been thought and said." Above I linked to the three pages that changed philosophy. Did you read them? Or, in the last few weeks, have you watched any other online videos of cats apart from Hank Green's Crash Course?

The psychologist Jerome Bruner approached the same problem from inside education. For Bruner, knowledge is structured: it is the organising frameworks and narratives that allow the learner to place new experience in relation to what they already know. His concept of the "spiral curriculum" follows from this: you do not teach a subject once and move on, but return to it repeatedly at greater depth, because understanding is not an event but a process of progressive structuring. Schools and teachers provide that structure, and through structure, meaning. That is what separates a curriculum from a database.

These two thinkers, Postman and Bruner, offer a way of reframing the education debate you started with. The question shifts from "knowledge or skills?" to "knowledge in the service of what?" If knowledge is just information - facts to be stored and retrieved - then the skills advocates are right to worry that it becomes the enemy of understanding. If knowledge is what Bruner says it is, structured frameworks for making sense of the world, then critical thinking depends on it entirely. The dichotomy dissolves. The debate was running on a bad definition of knowledge all along.

That is why the question of Lesson 2 - What is knowledge? - is not merely a technical puzzle for philosophers. Every curriculum embeds an answer to it, whether or not the people who wrote it know that they have done so. TOK asks you to notice the answer embedded in your own education and to decide whether you agree with it.

Bringing it together

So what is knowing?

This lesson moved from a live argument in education to the foundations of epistemology, and found the two are not as separate as they look. The knowledge-versus-skills debate cannot be resolved without first asking what knowledge is.

Plato's answer - Justified True Belief - was compelling enough to last 2,400 years. Gettier's counter-argument took three pages and changed the conversation permanently. Russell gave us the distinction between knowledge by acquaintance and knowledge by description, which maps onto connaître (knowing a city or person through direct experience) and savoir (knowing that something is the case). Ryle gave us the further distinction between knowing that and knowing how - procedural knowledge, which lives in the body and in trained skill rather than in propositions. Your own languages already encoded much of this. What philosophy did was make it explicit, precise, and available for examination.

The education debate is partly a debate about which of these kinds of knowledge schools value. The Swiss Maturité's traditional emphasis on savoir - propositional mastery - sits in interesting contrast to the IB's emphasis on knowing how to think. Both have a defensible answer to what matters most; they differ on emphasis. The double diploma puts you in the relatively unusual position of experiencing both at once.

You now have a philosophical vocabulary - JTB, propositional knowledge, procedural knowledge, knowledge by acquaintance and description, the Gettier problem - that will carry through the remaining six lessons on Knowledge and the Knower. These are the terms that make the arguments precise.

Next: Lesson 3 - Perspective 1: The Agent

Questions, assessments, films and other stuff.

Questions to think about

Is a justified false belief more valuable than an unjustified true one? What does your answer reveal about what you think knowledge is for?
Gettier’s cases show that something can be JTB without being knowledge. What is missing? Do you think the missing ingredient can be defined?
Can you know how to do something without knowing that any relevant propositions are true? What does this suggest about the relationship between propositional and procedural knowledge?
Russell argues that knowledge by acquaintance cannot be fully captured by description. Can you think of an example from your own experience that supports or challenges this?
Is information the same as knowledge? What would have to be added to information to make it knowledge?
Is the knowledge-rich curriculum really about knowledge, or about a particular type of knowledge? Which type? And whose?
French has savoir and connaître; English has only “know.” Does a language that lacks this distinction make certain knowledge problems harder to see? What other distinctions might be hidden inside words you take for granted?
If knowledge requires justification, can there be unjustified knowledge? Or is that simply a contradiction in terms?
Postman argues that modern culture produces information without wisdom. Is wisdom a form of knowledge? What would it mean to know wisely?

Exhibition connections
See more exhibition ideas and previous student work here

It is never too early to start to think about your TOK Exhibition, the ideas in this lesson connect strongly to three of the 35 prompts. Start noticing objects in the world around you that speak to these questions.

Prompt #25: "How can we distinguish between knowledge, belief and opinion?"
This lesson is built around exactly this question. A Gettier-type object, something that tracks the structure of justified belief failing to constitute knowledge, could anchor an exhibition exploring where belief ends and knowledge begins. Consider objects that encode a strong conviction that turned out to be wrong, or a belief that was true for the wrong reasons.

Prompt #11: Can new knowledge change established values or beliefs?
Gettier’s 2.5-page paper changed a 2,400-year-old philosophical consensus in one journal article. That is a remarkable example of new knowledge overturning established belief. An exhibition could examine the conditions under which new knowledge has the power to dislodge what was previously taken as certain, in philosophy, in science, in personal life.

Prompt #7: What are the implications of having, or not having, knowledge?
Christodoulou argues that the absence of background knowledge actively prevents students from acquiring the skills they need to think critically. An exhibition could explore the asymmetry between having and not having knowledge in different contexts, medical diagnosis, political participation, scientific literacy, and what follows from that asymmetry for questions of justice and power.

Feature films
For more see my 10 films for the TOK journey page.

🎬 WATCH — Memento (2000)
Directed by Michel Gondry

If your memories were erased, would you still be you? And if you are, in some important sense, your memories, your knowledge of your own past, what does that mean about the relationship between identity and knowledge? Joel’s mid-procedure realisation that he does not want to forget is one of cinema’s most striking statements about what personal knowledge means. My students can watch the film here.