Title: Nothing Is But What Is Not: Content, Intentionality and Error in Plato’s Theaetetus
Abstract: The Theaetetus offers a sustained investigation into the conditions on mental and semantic content through its vexed treatment of false judgement ascriptions. Focusing on the puzzle raised at 188a–c, I argue that Plato is grappling with a tension internal to object-dependent (de re) thought: if a thought’s content is partly constituted by its object, it becomes hard to see how one can be in error about that very object while still thinking of it. Plato, I argue, generates this difficulty from a plausible account of singular thought on which one can think of an object without possessing discriminatory knowledge of it. The resulting tension is illuminated—though not resolved—by the model of thought as the soul’s internal conversation with itself, which suggests that the original puzzle, while grounded in a plausible conception of mental content, trades on an informal fallacy of accident akin to the masked-man fallacy. If time permits, I conclude by drawing an analogy between this problem and Kripke’s puzzle about contradictory beliefs. This reading shows that Plato advances an object-involving theory of content that can accommodate error, while suggesting that contemporary object-dependent accounts of singular thought should not require discriminatory knowledge as a condition on intentionality.
