Philosophers have proven that a belief can be both true and justified without being knowledge

For centuries, philosophers followed Plato's definition of knowledge as 'justified true belief' (JTB). However, in 1963, Edmund Gettier published a three-page paper presenting scenarios where a person has a belief that is both true and supported by evidence, yet is only true by sheer luck. For instance, if you look at a stopped clock that happens to show the correct time, your belief about the time is justified and true, but you do not 'know' it.