Gettier Cases

For over two thousand years, philosophers accepted that knowledge could be defined as justified true belief. If you believe something, it's true, and you have good reasons for believing it, then you know it.

In 1963, philosopher Edmund Gettier published a three-page paper that challenged this definition with clever counterexamples. These "Gettier cases" have transformed epistemology (the study of knowledge).

You will be presented with several scenarios and asked whether the person in each case has knowledge. Please rely on your intuitions.