Edmund Gettier's Is Justified True Belief Knowledge?

The purpose of the article Is Justified True Belief Knowledge? by Edmund Gettier was to argue that justified true belief does not provide sufficient conditions for knowledge. He provides two points that he bases his argument on, and then offers two examples explaining his argument which are based on fallibility and luck. I will explain one of these examples and argue that a fourth condition, eliminating inappropriate causality, should be added to justified true belief to ensure that in the case provided, justified true belief does not fail to be knowledge. Justified true belief was the accepted definition of knowledge until Gettier wrote this article. It has three necessary conditions that were considered jointly sufficient for the definition of knowledge. It states that a subject knows a proposition if and only if the proposition is true, the subject believes in the proposition, and the subject is justified in believing that the proposition is true (121).

The first is that it is possible for the subject to be justified into believing a proposition that is false (121). An example of this may be running a test, but it produced a false positive or negative. Test results would be considered a justification for believing a proposition, but the test itself may be faulty. The second point is the fact that if a subject is justified in believing a proposition and a second proposition is deduced from the first, then the second proposition is also justified (121). An example would be me saying that it is raining outside. I am justified in believing this because I looked out my window and see the rain. I am able to deduce from that proposition that it is wet outside. Therefore, I am justified in saying that it is wet outside because I am justified in saying that it is