explain and evaluate the justified true belief analysis of knowledge and the Gettier problem, including proposed responses

What this dot point is asking

QCAA wants you to examine the central question of epistemology (the theory of knowledge): what is knowledge? You need the classical justified true belief (JTB) analysis, the famous Gettier problem that appears to refute it, and the main attempts to repair the analysis. This is foundational for the scepticism and rationalism-empiricism topics.

The answer

Knowledge versus belief

Not every true belief is knowledge. A lucky guess that turns out true is not knowing; neither is a true belief held for no reason. Epistemology asks what must be added to true belief to get knowledge. The kind in question is propositional knowledge: knowing that something is the case, as opposed to knowing how to do something or knowing a person.

The justified true belief analysis

The classical analysis, traceable to Plato's Theaetetus, holds that S knows that p if and only if three conditions are met:

1. Truth: p is true (you cannot know a falsehood).
2. Belief: S believes that p (you cannot know what you do not believe).
3. Justification: S is justified in believing p (you have adequate reasons or evidence, not a lucky guess).

Each condition seems necessary, and together they were long thought sufficient. The justification condition is meant to rule out lucky guesses.

The Gettier problem

In a three-page paper in 1963, Edmund Gettier presented cases where all three JTB conditions are met yet we would not say the person knows, because the belief is true by luck. A standard example: Smith has strong evidence that Jones will get a job and that Jones has ten coins in his pocket, so Smith infers "the person who gets the job has ten coins." In fact Smith himself gets the job, and Smith happens to have ten coins. Smith's belief is true, believed and justified, yet it is true only by coincidence, so it is not knowledge. The justification did not connect to what made the belief true.

The lesson: JTB is not sufficient for knowledge. There is a gap between being justified and the belief's being non-accidentally true.

Proposed responses

• No false lemmas (Gilbert Harman and others): add that the justification must not rely on any false belief. In the Gettier case, Smith's reasoning passed through the false belief that Jones would get the job, so this rules it out. Objection: some Gettier cases involve no false premise (for example "fake barn" cases).
• Reliabilism (Alvin Goldman): replace or supplement justification with the requirement that the belief be produced by a reliable process. In Gettier cases the lucky route is not reliable. Objection: the fake-barn case shows a reliable-looking perception can still yield a lucky truth.
• Defeasibility theory: knowledge is justified true belief for which there is no defeater, no further truth that, if known, would undermine the justification. The unknown truth (Smith will get the job) is such a defeater.
• Causal / safety / sensitivity conditions: require the right causal or modal connection between the fact and the belief, so the belief could not easily have been false.

No single repair is universally accepted, and some epistemologists conclude that knowledge may be unanalysable into simpler conditions.

Try this

Q1. State the three conditions of the justified true belief analysis. [3 marks]

• Cue. p is true; S believes p; S is justified in believing p.

Q2. Explain how a Gettier case shows JTB is not sufficient for knowledge. [4 marks]

• Cue. All three conditions are met, but the belief is true only by luck, so it is not knowledge.

Q3. Outline one proposed repair to the JTB analysis. [3 marks]

• Cue. For example reliabilism: the belief must be produced by a reliable process, excluding the lucky route.