In 1963, Edmund Gettier wrote a short article called, “Is Justified Truth Belief Knowledge?” and because of that question, it had generated wide-ranging philosophical arguments as to what is true knowledge. In short, he questioned the traditional “Justified Truth Belief” analysis, since this belief does not lead to true knowledge but only a product of sheer luck. The JTB tradition, for epistemologists, they would say that it is a necessary component of knowledge; but for Gettier, in contrary to the tradition, they are not sufficient. He proposed this through his paper and was come to know about later as the “Gettier cases.” These are cases or situations that one can have JTB, but not knowledge. In other words, one can have false belief but not false knowledge.
To prove, Gettier presented cases in which belief is only inferred from a justified false belief, which means that such belief cannot be true knowledge but only a mere luck that it is true. An example of these “Gettier cases” is the “Smith and Jones” case. As they apply on the same job, Smith thought that Jones is going to get the job just because the boss told him so. Also, he saw that Jones had ten coins in his pocket and that convinced him that the one who gets the job is the one who has ten coins in his pocket. But it turns out that Smith got the job and the boss’ testimony is false. Luckily, Smith also had ten coins in his pocket. That is what convinced him to believe that a person who has ten coins in his pocket will get the job. So, it seemed that Smith was lucked into being right. For Gettier, therefore, the justified truth belief is not knowledge. Because as for him, one does not KNOW just because he stumbled into the right answer.