I bet you know, or at least think you know, lots of things. But do you know what it means to know things? What do we mean by knowledge?
A common idea about the nature of knowledge holds that a person has knowledge when they hold an idea that meets the following criteria: -
- The idea the person holds is true
- The person believes the idea to be true
- The person is Justified in believing it to be true
This ideas is know as Justified True Belief. A person who has a justified true belief, can be said to have knowledge... or can they?
The Gettier problem
American philosopher Edmund Gettier
1963 three-page paper titled "Is Justified True Belief Knowledge?"
Gettier himself was not actually the first to raise the problem named after him; its existence was acknowledged by both Alexius Meinong and Bertrand Russell, the latter of which discussed the problem in his book Human knowledge: Its scope and limits. In fact, the problem has been known since the Middle Ages, and both Indian philosopher Dharmottara and scholastic logician Peter of Mantua presented examples of it.
The broken clock
The Cow in the field
The tob interview
The idea the person holds is true
The person believes the idea to be true
The person is Justified in believing it to be true
When the assumptions used to justify the belief are true.