The argument ‘to know or not to know’ in Theaetetus 187-200

Abstract

There is much discussion about how to interpret the role of the argument known as ‘Knowing or not Knowing’ in Theaetetus 188a-c. Some interpreters suppose that this role is dialectical and Plato is not committed to the truth of 188a-c. Others think that the argument shows Plato’s confusion about false belief at the time of Theaetetus. In my view there is a third alternative that does more justice to what Plato is doing in 187-200. I think that in Theaetetus 188a-c we have a version of Plato’s infallibility principle: the idea that epistêmê must necessarily be successful as knowledge.