Gettier Cases
Justified true belief that isn't knowledge
First published: E. Gettier, "Is Justified True Belief Knowledge?" *Analysis* 23 (1963): 121–123.
A three-page paper that dismantled two thousand years of definitions of knowledge.
Until 1963, the standard analysis of knowledge was: S knows that p if and only if (1) p is true, (2) S believes p, and (3) S is justified in believing p. Gettier produced two short counterexamples in which all three conditions are satisfied but intuitively no knowledge is present: someone has a justified true belief by *coincidence*, where the justification and the truth come apart. (Standard case: Smith has good reason to believe "Jones owns a Ford" and infers "Jones owns a Ford or Brown is in Barcelona"; the disjunction is true, but only because Brown is, by accident, in Barcelona — Jones has actually sold his Ford.) The case spawned an entire industry of attempts to add a fourth condition, none consensual; the more lasting effect was opening epistemology to externalist (reliabilist, tracking-based) accounts.
Formulation
Subject S has belief that p; p is true; S is justified in believing p; yet S's justification does not connect to what makes p true (the truth is a coincidence). Intuition: S does not know that p. Conclusion: JTB is insufficient for knowledge.
Dimensions Engaged
Observer
Targets Observer · Knowledge Extent: what does it take for a true belief to count as *knowledge* — what is the extra structure?
Information
Bears on Information · Ontological Status: knowledge requires an *informational* link between justification and truth, not merely the coincidence of both being present.
Responses — How Schools Engage
Affirms / takes the bait 2
Externalist naturalism (Goldman, Nozick, Sosa) takes Gettier as motivating a shift from internalist justification to causal/reliabilist conditions. Knowledge is a natural, not purely epistemic, achievement.
Skeptics welcome the result as confirmation: even apparently solid knowledge claims dissolve under pressure. Suspension of judgement remains the epistemically humble option.
Denies / rejects the premise 1
The Gettier project treats epistemology as the analysis of a folk concept by counterexample, sidestepping the phenomenological question of how knowing is *experienced*.
Reframes the question 2
Pragmatist epistemology denies the project: "knowledge" is a fluid, context-relative honorific. Gettier cases show only that a particular philosophical definition cannot do all the work, not that there is a single correct alternative.
A challenge to *post-Cartesian* internalist rationalism; classical rationalists insist that genuine knowledge is grounded in self-evident principles, where Gettier-style accidents are precluded.
Holds it inconclusive 1
The post-Gettier "fourth condition" project has produced reliabilism, tracking theories, sensitivity, safety, virtue accounts — no consensus. The case rules out JTB; it does not single out a successor.
Related Experiments
Experiments engaged by an overlapping set of schools — likely to surface the same fault lines.
Further reading
- Gettier (1963), op. cit.
- Shope, *The Analysis of Knowing* (1983)
- Williamson, *Knowledge and Its Limits* (2000)
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