Classroom activity · Epistemology
Being right is not always the same as knowing. Use four everyday cases to explain the difference.
You can type short notes below or print a blank copy. Typed notes stay on this page and are lost when it is closed or reloaded.
Start with a claim. This activity concerns knowing that something is the case—for example, that it is 3:00 p.m. It does not try to cover every meaning of “know,” such as knowing a person or knowing how to swim.
Does the person accept the claim as true? Confidence tells us about the person’s belief; it does not establish the fact.
Is the claim actually true in the case as described? A sincerely held belief can still be false.
What reason supports the belief? A familiar, normally reliable clock is a different basis from a guess.
“Justified true belief” is a useful starting account of knowledge, but it faces counterexamples. The final case asks whether these three conditions are enough.
Take two minutes to read the cases, six minutes to discuss them in pairs, and five minutes to compare reasons as a class. Use the final two minutes for the exit question.
Maya checks a library clock that she regularly uses and has good reason to trust. It is working correctly today. It shows 3:00 p.m., and it really is 3:00 p.m. Maya believes that it is 3:00 p.m.
What makes this an ordinary candidate for knowledge? Does Maya need to prove that error is impossible?
Jon has no clock, no view outside and no information about the time. He simply guesses that it is 3:00 p.m. and comes to believe his guess. By coincidence, it is 3:00 p.m.
Jon and Maya hold the same true belief. What difference in how they reached it matters?
Leah reads a familiar clock showing 3:00 p.m. She is certain it is correct, but it is running ten minutes slow. It is actually 3:10 p.m. She believes that it is 3:00 p.m.
Which condition fails, even if Leah has a reasonable basis for trusting the clock?
Sam checks a clock that has always been accurate and is normally well maintained. Unknown to Sam, it stopped at 3:00 earlier. Sam happens to look at it at exactly 3:00 p.m. Sam believes that it is 3:00 p.m.; this belief is true.
If Sam has the same apparent reason as Maya, is Sam’s true belief knowledge? Explain the role of luck.
Change one fact in the stopped-clock case so that Sam’s belief becomes a better candidate for knowledge. Explain why your change helps, rather than simply making Sam more confident.
Learning aim: students distinguish belief, truth and justification, then explain why a belief can meet the familiar three-part test yet seem true through luck. Assess the reasons students offer, not just their yes/no verdicts.
Belief and truth are present, with an ordinary reliable basis. Many everyday and fallibilist accounts treat this as knowledge. This is not a proof against skepticism, nor does it settle what every philosophical theory requires. Ask students whether ordinary knowledge must eliminate every conceivable possibility of error.
Belief and truth are present; the case supplies no supporting reason or reliable method. The guess is true by coincidence. Students should identify this missing basis rather than say merely that Jon lacks confidence.
The proposition “it is 3:00 p.m.” is false, so the standard truth condition fails. Leah’s sincerity does not make it true. Whether her belief is justified is a separate question; justification can be fallible on many accounts.
This is a familiar example of the problem often discussed alongside Gettier cases. On an account that judges justification by Sam’s available reasons, Sam appears to have a justified true belief. Many readers nevertheless deny knowledge because the truth is an accidental match: the same clock would give the same answer when the time is wrong. The stopped-clock example predates Gettier’s 1963 paper; it is not one of the two examples in that paper.
Some theories assess justification partly through reliability and may question whether Sam is justified at all. Let students state that alternative, but ask them to explain what it changes. The exercise does not establish one universally accepted analysis of knowledge.
A useful revision might give Sam a second, functioning time source and a good basis for trusting it. “Sam feels completely certain” changes confidence, not the faulty connection to the time. “Sam checks the same stopped clock twice” usually preserves the problem. Students may invent another solution if they explain how it reduces the relevant luck.
The explanations and classroom wording above are original. The conceptual distinctions and stopped-clock discussion draw on these references, checked on 29 October 2026.
Continue with knowledge, compare knowledge and belief, or explore a map of philosophical questions.