IB Philosophy 3.1.1 Nature of Knowledge Notes

What Is Knowledge?

The JTB Definition and Its Components

1. Unit 3 (Epistemology) examines the most fundamental questions in philosophy: what can we know, how do we know it, and what are the limits of human knowledge? While Units 1 and 2 explored what it means to be human and how we experience art, this unit turns inward to investigate the nature and structure of knowledge itself.
2. The overarching questions of Unit 3 include: "Can I know anything at all?", "What is the relationship between knowledge and certainty?", "Is knowledge culturally dependent?", and "What are the sources and limits of knowledge?" This opening topic addresses the most basic question: What is knowledge?
3. The traditional Western definition of knowledge, dating back to Plato's Theaetetus, says that knowledge is justified true belief (JTB). This means three conditions must all be met: the belief must actually be true, you must genuinely believe it, and you must have good reasons (justification) for holding it.
4. Each component of the JTB definition is necessary. Truth: you cannot know something false (you might believe it, but that belief does not constitute knowledge).
5. Belief: you cannot know something you do not believe (even if it happens to be true, it is not your knowledge unless you accept it).
6. Justification: you cannot know something by mere luck or guesswork. There must be reasons supporting the belief.

Gettier Cases and Responses to JTB

1. In 1963, Edmund Gettier published a short paper that revolutionised epistemology. He showed that there are cases where all three conditions of JTB are met, yet the subject does not genuinely know.
2. In Gettier cases, the belief is true, justified, and yet only true by coincidence. For example, if you see what appears to be a sheep in a field (actually a sheep-shaped rock), but there happens to be a real sheep hidden behind it, your belief "there is a sheep in the field" is justified and true, but not knowledge.
3. Gettier's challenge has prompted multiple responses. Some philosophers add a fourth condition, such as a no-defeater clause: the justification must not depend on any false beliefs.
4. Others, like Robert Nozick, propose a tracking theory: knowledge requires that the belief would not have been held if it were false (sensitivity) and would have been held if it were true (adherence). Applied to the sheep case, the belief fails the sensitivity condition because even if the real sheep had wandered away, you would still believe it.
5. Tracking theory explains why coincidentally true beliefs do not count as knowledge, and offers a sharper answer to Gettier than simply tacking on a fourth condition.
6. The IB syllabus also asks: "How do we experience the world around us?" This question connects epistemology to the phenomenology of perception discussed in Unit 1 (particularly 1.3.1 on consciousness). Our experience of the world is mediated by our senses, our cognitive frameworks, and our cultural context, all of which shape what we take to be knowledge.
7. Rene Descartes approached this question by asking what we can know with absolute certainty. In the Meditations on First Philosophy, Descartes employed methodological doubt: systematically doubting everything that could possibly be doubted until he reached an indubitable foundation: "I think, therefore I am" (cogito ergo sum).
8. This approach connects to the prescribed text 10.3.
9. The question of what knowledge is cannot be answered without also asking what truth is (explored in 3.1.2) and what the sources of knowledge are (explored in 3.1.3). These three topics form the foundation of the entire epistemology unit, and IB students should understand their interconnection.
10. For IB students, the JTB definition and Gettier's challenge are essential exam material. The key skill is the ability to explain the three conditions, construct a Gettier-style counterexample, and evaluate proposed solutions.
11. This analytical framework underpins the entire epistemology unit.

Rationalism and Empiricism

Rationalism: Reason as the Source of Knowledge