  In the first part of the Parmenides, the youthful Socrates sets out a theory of forms reminiscent of forms in the Phaedo and the Republic, and the main speaker, Parmenides, puts his theory to the test by focusing on two chief questions: What forms are there? and what is the nature of the relation between sensible things and their features and forms—the relation known as participation? At the end of the interrogation in Part I, when Socrates has failed to rescue his theory, and we might think that Plato should simply junk it, Parmenides comes to its defense, saying that if someone with an eye on all the difficulties denies that there are stable forms, he will have nowhere to turn his thought and will destroy the power of dialectic entirely (Parmenides 135b–c). Scholars look to the Sophist and Statesman and other late dialogues in the hope of finding Plato’s answer to the problems posed in the Parmenides. Does Plato continue to treat forms as he did in the Phaedo and Republic, despite the objections? Are the objections answerable and was Socrates simply too inexperienced to answer them adequately? Do the late dialogues record Plato’s on-going perplexity? Or do they seriously modify Plato’s earlier positions?