Back in the 1960’s, a philosopher named Edmund Gettier wrote a short paper called “Is Justified True Belief Knowledge?” For centuries, people thought you had knowledge when these three things were fulfilled:
1) It’s true
2) You believe it
3) You have good reason to believe it (it’s justified)
Gettier’s paper gave two different counterexamples where a man named Smith has justified true belief, but it’s not knowledge because he ended up attaining that belief by luck or accident. I recently wrote my own “Gettier case” for my Epistemology class here at MU. Here it is.
“When I was young, I walked into my house and heard my dad’s voice in the kitchen. I walked into the kitchen and saw him lying down on the floor with his head under the dishwasher, installing a new one. His face was hidden from me. I formed the belief ‘My dad is in the kitchen’ at that moment. As it turns out, the man under the new dishwasher was someone else, and my dad was standing in another corner of the room where I was not looking. The man’s body structure and even the sound of his voice was remarkably similar to my dad’s. So my belief that ‘My dad is in the kitchen’ was justified and it turned out to be true, but my knowledge came about by accident because the man I took for my father was someone else.”
My professor said “Short and sweet. A clear Gettier case.” 🙂