This morning I ended the first draft of my essay on ‘Plato’s defence of the Forms in the Parmenides’ with a cursory glance at Parmenides’ propaedeutic training, which forms the second, by far the greater part of the dialogue (the 1st part is 10, the 2nd part 30 Stephanus pages long, roughly speaking):
“The question is, whether and in what way Parmenides’ propaedeutic exercise fits Plato’s strategy in defending the forms in the dialogue. For it is not only much more thorough and radical in dismantling the forms with which Socrates challenged Zeno’s ‘many cannot be’ and Parmenides’ ‘All is one’, than the questioning to which Parmenides subjected Socrates, but it presents a serious challenge to Plato’s Forms. The forms Socrates brought in were derived from Socrates’ observation of the many things that exhibited the same form; their dismantling by Parmenides was therefore innocuous as far as the Forms presented in the Republic were concerned, to which Plato in the Parmenides directed the eyes of the reader, as I have argued. But in his propaedeutic exercise Parmenides begins by hypothesizing a single given form as being, and then the same form as not being; thus he can generate contradictory qualifications in any form he chooses to investigate; to elucidate his method, he chooses ‘the one’ as an example (135e-137b).
In the Parmenides the underlying supposition, shared by Socrates, Zeno, and Parmenides, is that whatever suffers contradictory qualifications cannot truly be; the forms investigated within the framework of the Parmenidean exercise are thus deprived of true being by virtue of the contradictions concerning them generated in the course of the exercise; true being belongs exclusively to ‘All that is one’ (128a-b). Plato appears to have been well aware of this problem when he wrote the Republic: ‘Of just and unjust, good and evil, and of every other form, the same remark holds: taken singly, each of them is one; but from the various combinations of them with actions and bodies and with one another, they are seen in all sorts of lights and appear many’ (476a4-7, tr. Jowett). But since he didn’t even dream of writing the Parmenides when he wrote those lines, he didn’t find it necessary to justify and ontologically establish the plurality of the Forms, each of which is just one. This task he had to undertake after he wrote the Parmenides, and he did so in the Sophist, in which he dons the garment of a Stranger from Elea; at the beginning of the Sophist Theodorus presents him as ‘a friend of the disciples of Parmenides and Zeno (hetairos tȏn amphi Parmenidȇn te kai Zȇnȏna, 226a3-4), but the Stranger proclaims himself to be a disciple of Parmenides at the point when he finds it ‘necessary in self-defence to put to the question the pronouncement of father Parmenides, and establish by main force that what is not, in some respect has being, and conversely that what is, in a way is not.’ (241d5-7, tr. Cornford). For only thus can Plato establish the plurality both in the realm of spurious being, in which the sophist finds his domicile, and in the realm of true being, which is accessible only to a true philosopher.
Concerning Parmenides’ propaedeutic exercise, one pole of Plato’s strategy in defending the Forms remains the same as concerning Parmenides’ questioning the forms introduced by Socrates. By pointing to his brothers Adeimantus and Glaucon, and his half-brother Antiphon in the introductory scene, Plato presents himself as someone who knew of Parmenides’ criticism of the forms from the time he himself conceived the Forms; the criticism was irrelevant concerning the Forms. But the other pole of his defence, his directing the eyes of the reader to the Republic, in which his Forms are presented, was powerless in respect of Parmenides’ propaedeutic exercise. Concerning it, Parmenides’ stepping out of his historical persona, in which he is presented in the dialogue, and turning into a prophet – ‘It will take a man of considerable natural gifts, who will be able to learn that there is a certain kind of each thing, and being by itself, and an even more admirable man who will discover it and will be able to teach it to someone else after examining sufficiently all these things (135a7-b2)’ – Parmenides looks into his own past as he braces himself for his propaedeutic exercise:
‘Antiphon said that Pythodorus said that he and Aristoteles and the others begged Parmenides to exhibit what he meant, and not refuse. Parmenides said, I must do as you ask. Yet really, I feel like the old racehorse in Ibycus [i.e. in Ibycus’ poem], who trembles with fear at the start of the race because he knows from long experience what lies in store. Ibycus compares himself (heauton apeikazȏn), forced (akȏn) as an old man (ephȇ kai autos houtȏ presbutȇs ȏn) to enter the lists of love against his will (eis ton erȏta anankazesthai ienai). When I remember how, at my age, I must traverse such and so great a sea of arguments, I am afraid.’ (136e5-137a6, tr. Allen)
And there comes an additional factor. Parmenides in the dialogue presents his exercise as indispensable, if Socrates is to be ‘fully trained and thoroughly discern the truth’ (136b4-5; cf. 135d5-6). Yet Plato’s disciples and followers knew well, for the Apology testified to it, that as a result of his encounter with Parmenides Socrates was left in the state of philosophic ignorance. And as far as Plato’s half-brother was concerned, Parmenides’ arguments, which he diligently rehearsed and learnt by heart as a youngster, left him uninterested in philosophy; instead, when he grew up, he became interested in horses (126c).”