The Three Divisions of Knowledge: Exploring A Priori, A Posteriori, and Experienced Knowledge

How do we come to know what we know? It’s one of the oldest questions in philosophy – and one that sits right at the heart of education. When a child learns that 2 + 2 = 4, is that the same kind of knowing as when they learn that fire is hot by touching something warm? And is either of those the same as a surgeon who has performed hundreds of operations and simply knows how to handle a crisis on the table? The answer, as philosophers have long argued, is no. Knowledge is not a single, uniform thing. It comes in fundamentally different forms – and understanding those forms matters deeply for how we teach and learn. Philosophers and epistemologists have broadly identified three divisions of knowledge: a priori, a posteriori, and experienced knowledge. Each has a distinct source, a distinct character, and a distinct role in education.

What is epistemology and why does it matter in education? 🔗

Before diving into the three divisions, it helps to understand the field that studies them. Epistemology is the branch of philosophy concerned with the nature, origin, and limits of knowledge. It asks not just what we know, but how we know it and why we are justified in believing it. For educators, epistemology is not merely academic. It shapes how curricula are designed, how lessons are sequenced, and how teachers decide when a student has truly “understood” something versus just memorized it. The three divisions of knowledge – a priori, a posteriori, and experienced – are among epistemology’s most foundational distinctions.

A priori knowledge: knowing through reason alone 🔗

A priori knowledge is knowledge that is independent of sensory experience. The term comes from Latin, meaning “from what comes before” – that is, before experience. You do not need to observe, touch, or test anything in the world to arrive at a priori truths. Pure reasoning or logical reflection is sufficient.

The clearest examples come from mathematics and logic. The statement “all bachelors are unmarried” is a priori – you do not need to meet a single bachelor to know it is true. The truth is contained within the very definition of the terms. Similarly, “2 + 2 = 4” is a priori because no empirical experiment is required to verify it; it follows necessarily from the rules of arithmetic.

The universality of a priori knowledge 🔗

One of the defining features of a priori knowledge is its universal validity. A priori truths do not vary by culture, time period, or individual circumstance. Mathematical principles, logical laws, and geometrical theorems hold everywhere and for everyone. As the Internet Encyclopedia of Philosophy explains, a priori knowledge is knowable independently of any experience other than that of learning the language in which a proposition is expressed. Once you understand what the words mean, the truth becomes self-evident through reason alone.

The 18th-century German philosopher Immanuel Kant gave this distinction its modern philosophical weight. Kant argued that some knowledge is what he called “synthetic a priori” – meaning it extends our understanding of the world yet does not require sensory experience to establish. His work made it clear that not all knowledge about the world is derived from observation, challenging the earlier empiricist assumption that the mind begins as a blank slate.

A priori knowledge in the classroom 🔗

In education, a priori knowledge forms the backbone of subjects like mathematics, formal logic, and certain areas of linguistics. When a teacher introduces students to the concept that the angles of a triangle always add up to 180 degrees, no ruler or protractor is strictly needed – the proof follows from the axioms of Euclidean geometry. The role of the teacher here is to guide students through the reasoning process until the truth becomes self-evident. This type of instruction builds students’ capacity for deductive thought and structured argumentation, skills that are transferable across all disciplines.

A posteriori knowledge: knowing through experience and observation 🔗

A posteriori knowledge, by contrast, is knowledge that depends entirely on experience. The term means “from what comes after” – after observation, after experimentation, after sensory engagement with the world. You cannot arrive at a posteriori truths through pure reasoning; you must go out and look, test, or measure.

Examples are everywhere in daily life and science. “The sky is blue,” “water boils at 100°C at sea level,” and “the capital of India is New Delhi” are all a posteriori claims. As the Wikipedia article on a priori and a posteriori points out, the proposition “George V reigned from 1910 to 1936” is something one must come to know a posteriori – it is an empirical fact that reasoning alone cannot establish. You must consult historical records or evidence.

The role of empirical investigation 🔗

A posteriori knowledge is the engine of science. Every scientific discipline – biology, chemistry, physics, history, economics – builds its knowledge base through observation and evidence. The scientific method itself is fundamentally a posteriori: hypotheses are formed and then tested against data gathered from the real world. This is why scientific knowledge can change – new evidence may revise or overturn old conclusions, something that can never happen with a priori truths like mathematical axioms.

The distinction between the two types of knowledge is neatly illustrated by this contrast: knowing that “if it rains, the ground will get wet” is a priori reasoning about a general relationship, while actually stepping outside and seeing that the ground is wet today is a posteriori knowledge – drawn from direct sensory experience of this specific situation, as noted by the Philosophy Institute.

A posteriori knowledge in the classroom 🔗

This division of knowledge dominates a large part of formal schooling. Science experiments, field trips, case studies, historical source analysis, and even classroom debates all engage a posteriori learning. Students build knowledge by engaging with evidence – reading primary sources, conducting lab experiments, or analyzing real-world data. A teacher using a posteriori methods is essentially training students to be careful observers and evidence-based thinkers, which is a cornerstone skill in both academic and professional life.

It is also worth noting that a priori and a posteriori knowledge are not rivals – they work together. A scientist uses logical reasoning (a priori) to design an experiment and interpret results, while relying on empirical data (a posteriori) to test the hypothesis. Neither form alone is sufficient for a complete understanding of the world.

Experienced knowledge: knowing by living through it 🔗

The third division is perhaps the most personal and the hardest to transfer. Experienced knowledge – also called experiential knowledge – is knowledge that can only be acquired by actually going through something. It cannot be fully conveyed through words, textbooks, or logical argument. It must be lived.

The classic illustration comes from philosophy of mind. Explaining the colour blue to someone who has been blind from birth is impossible, no matter how precise the language. The person can learn a priori truths about the wavelength of blue light and a posteriori facts about how most people describe the sky – yet they cannot have the direct experiential knowledge of what blue looks like. As the Wikipedia entry on experiential knowledge explains, this type of knowledge refers to understanding that can only be acquired through experience itself – like knowing what it is like to see colours.

Experienced knowledge vs. propositional knowledge 🔗

Philosophers draw a sharp line between propositional knowledge (knowing that something is the case) and experiential knowledge (knowing what it is like to experience something). You can read every book ever written about grief and still not fully know grief until you have experienced loss yourself. A medical textbook can describe pain in clinical detail, but the knowledge a patient has of their own chronic pain is of a fundamentally different kind – richer, more immediate, and irreducible to any set of propositions.

Bertrand Russell captured part of this in his distinction between “knowledge by description” and “knowledge by acquaintance” – the latter being a direct, non-inferential familiarity with something that only comes from encountering it directly. Philosopher Matt Duncan, writing in Oxford Studies in Philosophy of Mind, argues that experience is not merely a pathway to knowledge – in an important sense, experience itself constitutes a kind of knowledge.

Experienced knowledge in practice and education 🔗

Experienced knowledge is also the form Aristotle had in mind when he argued that practical wisdom – what he called phronesis – cannot be learned solely from books. In his Nicomachean Ethics, Aristotle illustrated this with medicine: a doctor who knows in theory that light foods are healthy but cannot recognize which specific foods are light will fail where the experienced practitioner succeeds. As one analysis of this passage puts it, practical knowledge tied to real-world experience is often more effective than pure theoretical knowledge without any application.

In education, this translates directly into the value of internships, clinical placements, apprenticeships, and hands-on practice. A trainee teacher can study pedagogy for years, but the knowledge that comes from actually standing in front of a class – reading the room, adjusting to unexpected moments, managing real dynamics – is experienced knowledge that no curriculum alone can provide. As researchers in educational phenomenology have argued, learning from the lived experience of others is not just valuable in education – it is foundational.

D.T. Suzuki’s Zen observation captures it sharply: “Mere talking of fire will not make the mouth burn.” No amount of propositional description substitutes for the direct encounter.

How the three divisions work together 🔗

These three forms of knowledge are not in competition with each other – they are complementary layers of a complete education. A priori knowledge gives learners the tools of reasoning and the certainty of logical truth. A posteriori knowledge grounds them in the observable facts of the world. Experienced knowledge deepens their understanding in ways that observation and reasoning alone cannot reach.

Consider how a medical student develops. They begin with a priori knowledge – the logic of biological systems and the structure of diagnoses. They build a posteriori knowledge through clinical science – studying diseases, reading research, interpreting test results. But it is only through years of practiced clinical experience – seeing patients, making calls under pressure, navigating outcomes – that they develop the experienced knowledge that marks the seasoned clinician. All three are required. None is sufficient alone.

For teachers, recognizing these three divisions is more than an academic exercise. It clarifies what kind of learning a lesson is aiming at, and therefore how it should be designed. Teaching a priori content calls for logical explanation and structured proof. Teaching a posteriori content calls for evidence, investigation, and inquiry. And cultivating experienced knowledge calls for practice, reflection, and real-world engagement – the things that no worksheet can replace.

What do you think? When you consider the subjects you’ve taught or studied, which of the three divisions of knowledge do you think receives the least attention in formal education – and what might be lost as a result? Is there a form of knowledge that you believe can never be fully taught in a classroom, no matter how well-designed the lesson?

References

1. https://en.wikipedia.org/wiki/Epistemology
2. https://iep.utm.edu/apriori/
3. https://www.britannica.com/topic/epistemology/A-priori-and-a-posteriori-knowledge
4. https://en.wikipedia.org/wiki/A_priori_and_a_posteriori
5. https://philosophy.institute/ancient-medieval/a-priori-vs-a-posteriori-knowledge/
6. https://en.wikipedia.org/wiki/Experiential_knowledge
7. https://philarchive.org/archive/DUNEIK
8. https://academic.oup.com/book/39637/chapter/339599719
9. https://scholarblogs.emory.edu/basicproblems002/2015/02/01/experience-vs-knowledge/
10. https://journals.sagepub.com/doi/full/10.1177/1609406920942066