The Gettier problem, in the field of epistemology, is a landmark philosophical problem with our understanding of knowledge. Attributed to American philosopher Edmund Gettier, Gettier - type counterexamples (called "Gettier - cases '') challenged the long - held justified true belief (or JTB) account of knowledge. On the JTB account, knowledge is equivalent to justified true belief, and if all three conditions (justification, truth, and belief) are met of a given claim, then we have knowledge of that proposition. In his three - page 1963 paper, titled "Is Justified True Belief Knowledge? '', Gettier showed, by means of two counterexamples, that there were cases where individuals had justified the true belief of a claim but still failed to know it. Thus, Gettier claimed to have shown that the JTB account was inadequate -- it could not account for all of the knowledge. The JTB account was first credited to Plato, though Plato argued against this very account of knowledge in the Theaetetus (210a).
who came up with the tripartite theory of knowledge
Edmund Gettier