Justified true belief is a definition of knowledge that is most frequently credited to Plato and his dialogues. The concept of justified true belief states that in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must also have justification for doing so. In more formal terms, a subject S knows that a proposition P is true if and only if:
- P is true
- S believes that P is true, and
- S is justified in believing that P is true
This theory of knowledge suffered a significant setback with the discovery of Gettier problems, situations in which the above conditions were seemingly met but that many philosophers disagree that anything is known. Robert Nozick suggested a clarification of "justification" which he believed eliminates the problem: the justification has to be such that were the justification false, the knowledge would be false.
Famous quotes containing the words justified, true and/or belief:
“But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and in the Spirit of our God.”
—Bible: New Testament, 1 Corinthians 6:11.
“The rights of citizenship will be taken away from all Jews and other non-Aryans. They are inferior and therefore enemies of the state. It is the duty of all true Aryans to hate and despise them.”
—Charlie Chaplin (1889–1977)
“It is impossible to calculate the moral mischief, if I may so express it, that mental lying has produced in society. When a man has so far corrupted and prostituted the chastity of his mind as to subscribe his professional belief to things he does not believe he has prepared himself for the commission of every other crime.”
—Thomas Paine (1737–1809)