At Theaetetus 187b, Socrates’ interlocutor Theaetetus offers a definition of knowledge as true belief. Since Socrates has already argued that Theaetetus’ first definition of knowledge as perception is inadequate, the discussion has moved away from perceptual accounts of knowledge to the relationship between beliefs or judgments and knowledge. Even though Theaetetus’ definition of knowledge as true belief is not immediately refuted, Socrates instead proposes that he and Theaetetus investigate the possibility of false judgments. That is, Socrates proposes that they investigate how it is possible for someone to believe things which are false.
This project, then, is concerned with this stretch of the Theaetetus; Plato’s investigation into the possibility of false judgments. One of the most important questions that arise when reading this passage is why the discussion into the possibility of false judgments is brought up at all. In this dissertation I shall argue, contrary to some scholars, that the discussion of false belief in the Theaetetus has a distinct purpose, namely, to refute Protagoras’ suggestion that false beliefs are impossible. Plato is, throughout this passage, genuinely bothered by the problem of falsehood and seeks to find a satisfactory resolution. He seeks to find a resolution so that he may, contrary to Protagoras, show that false judgments are possible.
In the course of defending this claim, I shall investigate the two primary impediments to accounting for falsity. These first two puzzles argue that false beliefs cannot occur if certain assumptions are made. After investigating these two puzzles, I shall outline and interpret Plato’s three proposed solutions to these two puzzles. As I shall argue, while Plato’s attempt to overcome the difficulties of the two puzzles fails, he is genuinely bothered by the problem of falsehood. Various reasons have been offered by commentators for the failure of Plato’s account. While this is the case, I shall argue that what makes false belief unaccountable for Plato at this juncture of his career are certain assumptions about the mind’s relationship between its judgments and the objects of its judgments.