Stallbaum, after reciting many different hypothetical interpretations from those interpreters who had preceded him, says (Prolegg. p. 265), “En lustravimus tandem varias interpretum de hoc libro opiniones. Quid igitur? verusne fui, quum suprà dicerem, tantam fuisse hominum eruditorum in eo explicando fluctuationem atque dissensionem, ut quamvis plurimi de eo disputaverint, tamen ferè alius aliter judicaverit? Nimirum his omnibus cognitis, facilè alicui in mentem veniat Terentianum illud — Fecisti propé, multo sim quam dudum incertior.”
Brandis (Handbuch Gr.-Röm. Phil. s. 105, pp. 257-258) cannot bring himself to believe that dialectical exercise was the only purpose with which Plato composed the Parmenides. He then proceeds to state what Plato’s ulterior purpose was, but in such very vague language, that I hardly understand what he means, much less can I find it in the Antinomies themselves. He has some clearer language, p. 241, where he treats these Antinomies as preparatory ἀπορίαι.
[57] Ast, Platon’s Leben und Schriften, pp. 239-244; Schleiermacher, Einleit. zum Parmen. pp. 94-99; Strümpell, Geschichte der Theoretischen Philosophie der Griechen, sect. 96, pp. 128-129.
I do not agree with Socher’s conclusion, that the Parmenides is not a Platonic composition. But I think he is quite right in saying that the dialogue as it now stands performs all that Parmenides promises, and leaves no ground for contending that it is an unfinished fragment (Socher, Ueber Platon’s Schriften, p. 286), so far as philosophical speculation is concerned. The dialogue as a dramatic or literary composition undoubtedly lacks a proper close; it is ἄπους or κολοβὸς (Aristot. Rhetor. iii. 8), sinning against the strict exigence which Plato in the Phædrus applies to the discourse of Lysias.
The Demonstrations or Antinomies considered. They include much unwarranted assumption and subtlety. Collection of unexplained perplexities or ἀπορίαι.
That the demonstrations include assumption both unwarranted and contradictory, mingled with sophistical subtlety (in the modern sense of the words), is admitted by most of the commentators: and I think that the real amount of it is greater than they admit. How far Plato was himself aware of this, I will not undertake to say. Perhaps he was not. The reasonings which have passed for sublime and profound in the estimation of so many readers, may well have appeared the same to their author. I have already remarked that Plato’s ratiocinative force is much greater on the negative side than on the positive: more ingenious in suggesting logical difficulties than sagacious in solving them. Impressed, as Sokrates had been before him, with the duty of combating the false persuasion of knowledge, or premature and untested belief, — he undertook to set forth the pleadings of negation in the most forcible manner. Many of his dialogues manifest this tendency, but the Parmenides more than any other. That dialogue is a collection of unexplained ἀπορίαι (such as those enumerated in the second book of Aristotle’s Metaphysica) brought against a doctrine which yet Plato declares to be the indispensable condition of all reasoning. It concludes with a string of demonstrations by which contradictory conclusions (Both and Neither) are successively proved, and which appear like a reductio ad absurdum of all demonstration. But at the time when Plato composed the dialogue, I think it not improbable that these difficulties and contradictions appeared even to himself unanswerable: in other words, that he did not himself see any answers and explanations of them. He had tied a knot so complicated, that he could not himself untie it. I speak of the state of Plato’s mind when he wrote the Parmenides. At the dates of other dialogues (whether earlier or later), he wrote under different points of view; but no key to the Parmenides does he ever furnish.
Even if Plato himself saw through these subtleties, he might still choose to impose and to heap up difficulties in the way of a forward affirmative aspirant.
If however we suppose that Plato must have had the key present to his own mind, he might still think it right to employ, in such a dialogue, reasonings recognised by himself as defective. It is the task imposed upon Sokrates to find out and expose these defective links. There is no better way of illustrating how universal is the malady of human intelligence — unexamined belief and over-confident affirmation — as it stands proclaimed to be in the Platonic Apology. Sokrates is exhibited in the Parmenides as placed under the screw of the Elenchus, and no more able than others to extricate himself from it, when it is applied by Parmenides: though he bears up successfully against Zeno, and attracts to himself respectful compliments, even from the aged dialectician who tests him. After the Elenchus applied to himself, Sokrates receives a farther lesson from the “Neither and Both” demonstrations addressed by Parmenides to the still younger Aristotle. Sokrates will thus be driven, with his indefatigable ardour for speculative research, to work at the problem — to devote to it those seasons of concentrated meditation, which sometimes exhibited him fixed for hours in the same place and almost in the same attitude[58] — until he can extricate himself from such difficulties and contradictions. But that he shall not extricate himself without arduous mental effort, is the express intention of Parmenides: just as the Xenophontic Sokrates proceeds with the youthful Euthydemus and the Platonic Sokrates with Lysis, Theætetus, and others. Plausible subtlety was not unsuitable for such a lesson.[59] Moreover, in the Parmenides, Plato proclaims explicitly that the essential condition of the lesson is to be strictly private: that a process so roundabout and tortuous cannot be appreciated by ordinary persons, and would be unseemly before an audience.[60] He selects as respondent the youngest person in the company, one still younger than Sokrates: because (he says) such a person will reply with artless simplicity, to each question as the question may strike him — not carrying his mind forward to the ulterior questions for which his reply may furnish the handle — not afraid of being entangled in puzzling inconsistencies — not solicitous to baffle the purpose of the interrogator.[61] All this betokens the plan of the dialogue — to bring to light all those difficulties which do not present themselves except to a keen-sighted enquirer.
[58] Plato, Symposion, p. 220 C-D: compare pp. 174-175.
In the dialogue Parmenides (p. 130 E), Parmenides himself is introduced as predicting that the youthful Sokrates will become more and more absorbed in philosophy as he advances in years.