Parmenides is fascinating as a penetrating criticism of the theory of ideas, or forms, in its undeveloped state, as propounded by the youthful Socrates. According to the report given by Antiphon—a report of the conversation between Parmenides and Socrates, with some assistance from Zeno and Aristoteles—Socrates met Parmenides when the latter was about sixty-five years old and famous for his poem Peri physes (fifth century b.c.e.; The Fragments of Parmenides, 1869; commonly known as On Nature), in which he argued, with great ingenuity, that “All is one.” It may very well be that this conversation occurred as reported, but what is more likely is that Plato, having heard that at one time young Socrates met the aging Parmenides, used this bit of historical information as a dramatic center about which to build a summary of Parmenidean criticism of his theory of ideas, taking some of the edge off the criticism by portraying Socrates as clever but immature in his thinking. Consequently, Parmenides serves as evidence that Plato was never entirely satisfied with the theory of ideas. Like all great philosophers, he kept coming back to his central thesis, subjecting it to critical scrutiny and modifying it in accordance with the discoveries of its weaknesses.
The presentation of the dialogue is somewhat complicated. Cephalus repeats an account originally given by Antiphon of the...
(The entire section is 518 words.)