In Plato's early dialogues, Socrates typically draws from his interlocutors definitions of moral terms, then demonstrates that these positions or their consequences are inconsistent with the definitions they have offered. On numerous occasions in the early dialogues, Socrates claims that this method will yield truth. This study argues that Plato entertains a theory of truth according to which consistency is sufficient for truth, rescuing him from the charge of having confused consistency with truth and solving the puzzle of Socratic ignorance. The author also suggests a new theory of Plato's philosophical development: Middle and Late Plato did not abandon Socratic philosophy; rather, he sought to secure its foundations. The late Plato returns to Socratic method in the penultimate work of the corpus, "Philebus".