A Path to Perfect Knowledge in Plato's 'Theaetetus'

ABSTRACT Plato’s Theaetetus has often been thought to contain an epistemological regress. According to an argument in the final part of the dialogue, knowledge is true belief with an account. On this view, knowledge of x is based on knowledge of an account of x. But an account of x is itself composed of epistemic items which need to be based on further known accounts, and so the regress ensues. According to some, Plato endorses epistemological coherentism in the Theaetetus. On this view the regress is blocked since epistemic accounts reciprocate, and epistemic items are known by interrelating the items in question within their restricted domains. In this paper, I argue that the there is no support from the text for restricting knowledge within domains—indeed, there are even conceptual worries with this restriction. But without this restriction, a coherentist reading of knowledge in Theaetetus fails since it entails that knowledge of anything requires knowledge of everything per impossibile. I offer a remedy for this issue by arguing that Plato countenanced an intermediate cognitive-epistemic state which we can call Imperfect Knowledge. Perfect Knowledge of x can rest, I argue, on an account whose items are known only imperfectly provided certain conditions are met. On the view I promote, learning begins with perception, proceeds to true judgement, attains imperfect knowledge and ultimately attains perfect knowledge. The upshot of my argument is novel support for the coherentist interpretation of learning and knowledge in Theaetetus.