 In the 1960s, a wide range of epistemologists were absorbed by the question: what does it take for a belief to amount to knowledge? It was generally agreed that for a person, S, to know some proposition p, at least three conditions must be met. First, p must be true. Second, S must believe p. And third, S must be justified in believing p. Thus, knowledge requires justified true belief. But does the satisfaction of these three conditions suffice to entail that S knows p? Unfortunately, as Edmund Gettier (1963) showed with several convincing cases, justified true belief doesn’t guarantee knowledge.