Edmund Gettier is famous for his widely cited paper proposing what is known as the "Gettier Problem." His 1963 article in Analysis, "Is Justified True Belief Knowledge?" challenged the traditional definition of knowledge, accepted since Plato (though Plato/Socrates arguably questioned this definitionA. Although typical Gettier examples are little more than wordplay, the Gettier Problem looms large when philosophy has been reduced to problems in logic and language. Similar embarrassments for analytic language philosophy are the cleverly worded examples of "Frankfurt cases" designed to deny alternative possibilities, the essential first stage in the two-stage model of free will.