Smith justifiably believes his colleague Jones will get a promotion (based on reliable inside information). From this, Smith infers: 'The person getting the promotion drives a red car' — because he knows Jones drives a red car. Unknown to Smith, it is actually Smith himself who gets the promotion, and Smith also drives a red car. Smith's belief is justified, true, and based on valid inference. Does Smith know that the person getting the promotion drives a red car?
AYes — the belief is justified, true, and based on a valid inference, which is all JTB requires
BNo — because Smith's belief, though justified and true, is true for the wrong reason: his justification tracked Jones, but the truth-maker is his own car
CNo — because Smith's original belief about Jones was false, so the inference is also false
DYes — truth and justification are both present, and the reason for truth is irrelevant to knowledge
This is a Gettier case. Smith's belief is justified (he had good evidence about Jones), true (the promotee does drive a red car), and believed. But he does not know it, because the truth is connected to his justification only accidentally. His justification was about Jones; the actual truth-maker is his own situation. This is the structural feature of all Gettier cases: justification and truth are present, but they are linked by luck rather than by the justification tracking the actual truth-maker. Options A and D represent the JTB view that Gettier's cases refute.
Question 2 Multiple Choice
Henry is driving through a region filled with realistic barn facades, though he doesn't know this. He looks directly at the one real barn in the area and forms the justified true belief 'that's a barn.' What makes this a Gettier-style case, and what does it reveal that the 'no false lemmas' response to Gettier cannot handle?
AHenry's belief is unjustified because he should have checked whether it was a facade
BThe case is not a Gettier problem because Henry's belief happens to be true
CHenry's belief contains a false intermediate step: he assumed all barn-like shapes are real barns
DHenry has no false intermediate beliefs, yet most philosophers say he doesn't know — revealing that epistemic luck, not false lemmas, is the core problem with JTB
The 'no false lemmas' response to Gettier says: your belief cannot depend on any false intermediate belief. This blocks Gettier's original cases, but the fake barns case has no false lemma — Henry's inference is direct, and his perceptual belief is formed without any false intermediate step. Yet the environment was rigged against reliable barn-perception. Henry's belief could easily have been false (he was lucky to look at the one real barn). This case reveals that the real problem is not false lemmas but epistemic luck: the belief is true, but only by coincidence, given how the world was arranged around Henry.
Question 3 True / False
Gettier cases demonstrate that justification is not necessary for knowledge — that you can have knowledge without any justification at most.
TTrue
FFalse
Answer: False
Gettier cases demonstrate that justification is not *sufficient* for knowledge — that JTB (justified true belief) is not enough. They do not challenge the necessity of justification. In all Gettier cases, the agent has justification; that is precisely why the cases are puzzling. The problem is that justification, truth, and belief can all be present yet knowledge can still be absent, because the three components are connected only accidentally. The long-standing response to Gettier seeks a *fourth* condition to add to JTB, not to remove justification.
Question 4 True / False
Adding a 'no false lemmas' condition to JTB — requiring that your belief not depend on any false intermediate belief — successfully blocks most Gettier-style counterexamples.
TTrue
FFalse
Answer: False
The 'no false lemmas' response blocks Gettier's original cases (both depend on the false belief that Jones will get the job or that Jones has coins in his pocket). But Gettier-style cases can be constructed without any false intermediate beliefs. The fake barns case is the canonical example: Henry's justified true belief that 'that's a barn' involves no false lemma, yet intuitively he doesn't know it. This shows that the real issue is epistemic luck — the belief being true in a way that could easily have been false — which 'no false lemmas' does not address.
Question 5 Short Answer
What structural feature do all Gettier cases share, and why does this feature mean that having justified true belief is not enough for knowledge?
Think about your answer, then reveal below.
Model answer: In every Gettier case, the justification is a reliable indicator of some fact, but the belief turns out true for a different reason than the one the justification tracks. Justification and truth are present, but they are connected only accidentally — the belief could easily have been false despite the justification, or is true because of a lucky coincidence rather than because the justification reliably tracked the truth-maker.
The recipe for constructing a Gettier case makes the structure explicit: start with justified belief in a false proposition P; from P, validly infer a true proposition Q. The belief in Q is justified (by inheritance from P), true (by construction), but not known — because the false P was the epistemic route to Q, and the truth of Q is a coincidence unrelated to that route. What genuine knowledge requires is that the justification actually track the truth-maker — the connection between why you believe something and why it's true must not be merely accidental. This is what drives post-Gettier epistemology toward concepts like reliability, proper function, and the elimination of epistemic luck.