Knowledge and the Gettier Problem (SACE Stage 2 Philosophy)

What this dot point is asking

You need to set out the JTB definition, show why Gettier cases defeat it, and assess whether any proposed fix succeeds.

The justified true belief analysis

The standard account holds that a subject knows that p if and only if three conditions are met. First, p is true. Second, the subject believes that p. Third, the subject is justified in believing that p. Truth rules out knowing falsehoods, belief rules out knowing what you do not accept, and justification rules out lucky guesses. This justified true belief (JTB) analysis goes back to Plato's Theaetetus and was the default view for centuries.

Gettier's counterexamples

In a short 1963 paper, Edmund Gettier argued that JTB is not sufficient. Consider a worker, Smith, who has strong evidence that a colleague named Jones will get a job and that Jones has ten coins in his pocket. Smith concludes that the person who gets the job has ten coins in their pocket. In fact Smith himself gets the job, and Smith, as it happens, also has ten coins in his pocket. Smith's belief was justified and true, yet it was true only by luck, since his evidence was about Jones. Intuitively Smith did not know.

The general structure is a justified false belief that, through coincidence, yields a true conclusion. Because the truth of the belief is disconnected from the justification, we are reluctant to call it knowledge. Gettier cases show that JTB rules out too little.

Responses to Gettier

Several repairs have been proposed.

The no false lemmas condition adds that the justification must not depend on any false belief. In the coins case, Smith reasoned through the false belief that Jones would get the job, so the case is excluded. The trouble is that other Gettier cases, such as Alvin Goldman's fake-barn example, do not obviously rely on a false premise yet still defeat knowledge.

Reliabilism, defended by Alvin Goldman, replaces justification with reliable belief formation. A belief counts as knowledge when produced by a process that reliably yields truths. In fake-barn country, where a driver looks at the one real barn among many facades, the perceptual process is unreliable in that environment, so the view explains the lack of knowledge. Critics object that reliabilism faces the generality problem of specifying which process is the relevant one.

Virtue epistemology, developed by Ernest Sosa and John Greco, holds that knowledge is true belief that succeeds because of the agent's intellectual virtue or competence, not because of luck. In Gettier cases the success is due to luck rather than competence, so it is not knowledge. This elegantly diagnoses the cases but invites debate over what counts as a cognitive virtue.

Evaluating

A good answer recognises that Gettier cases reveal a single underlying problem: knowledge seems incompatible with the kind of luck that makes a justified belief true by accident. Each repair tries to rule out that luck. None commands universal agreement, and some philosophers, following Timothy Williamson, conclude that knowledge cannot be analysed into simpler conditions at all and should be treated as basic. The lasting lesson is that a satisfying theory of knowledge must connect the truth of a belief to the way the believer arrived at it.