Plato’s first attempt to turn Dionysius into a philosopher-king, which took place in 367-366, ended with a compact between the two: Dionysius’ would invite Plato back ‘as soon as he had made his own power more secure’ and Plato promised that he would return (Seventh Letter 338a5-b2). When Plato arrived to Sicily as promised (in 361), he pointed out to Dionysius what true philosophy was all about, how many preliminary subjects it entailed and how much labour: ‘For on hearing this, if the pupil be truly philosophic … he believes that he has been shown a marvellous pathway and that he must brace himself at once to follow it … after this he braces both himself and him who is guiding him on the path, nor does he desist until either he has reached the goal of all his studies, or else has gained such power as to be capable of directing his own steps without the aid of the instructor … this, then, was the purport of what I said to Dionysius on that occasion’ (340b7-341a8, tr. Bury). Clearly, Plato was prepared to devote the rest of his life to this task, which means that ever since he returned to Athens in 366 he faced the task of preparing his disciples in the Academy for doing philosophy without him, or rather, how to ensure his spiritual presence among them after his physical departure.
Plato’s conception of the state ruled by philosophers as the only properly governed state stands and falls with his theory of Forms. Therefore, all those who feared Plato’s influence on the court of Dionysius must have been interested in debunking Plato’s Forms, and so were the sophists invited to the court. Aristotle’s Metaphysics indicates that even in Plato’s Academy arguments against the Forms were in vogue. And so in the Parmenides Plato undertook to defend the Forms by voicing the cardinal arguments against them, pointing out that although such arguments of necessity pertained to the Forms, they had no validity in the eyes of those who could see the Forms. This dialogue fulfils this task jointly with the Republic, to which the eyes of the readers are directed in its opening line: ‘When we arrived at Athens from our home in Clazomenae, we met Adeimantus and Glaucon in the Agora.’ In the Republic these two brothers of Plato compel Socrates to transcend his philosophic ignorance (Republic 357a-368c) and outline the state governed by philosophers, that is by those who can see the Forms.
Although the Parmenides fulfils the task of defending the Forms jointly with the Republic, let me consider their specific contributions, beginning with the former, the dramatic setting of which suggests that Plato had been acquainted with arguments against the Forms in his early days, and that he found those arguments irrelevant. For Plato’s half-brother Antiphon, only a few years younger than Plato, diligently rehearsed arguments against the Forms in his teens (meirakion ȏn), to which his brother Adeimantus testifies (Parm. 126c6-7).
The modern Platonic scholarship has deprived itself of the possibility to perceive and appreciate this point ever since it was ‘definitely established’ that the ancient tradition, according to which Plato’s first dialogue was the Phaedrus, was ‘patently absurd’ (Cf. e.g. R. Hackforth’s ‘Introduction’ to his translation of the Phaedrus, Cambridge, 1972, p. 3), for in the Phaedrus Plato brings the Forms prominently into view. (I defend the ancient tradition concerning the dating of the Phaedrus in The Lost Plato on my website.)
Another misconception that has bearing on this problem is the belief that ‘Diogenes 3. 6 reports that Plato knew Socrates only from the age of twenty’. (Debra Nails, The People of Plato, Hackett Publishing Company, 2002, p. 156). Plato must have known Socrates from his childhood; his uncle Charmides was a friend of Socrates as we know both from Plato and from Xenophon.
Aristotle, one of the Thirty (ton tȏn triakonta genomenon, Parm. 127d2-3), was Parmenides’ discussion partner in the Parmenides, and Plato says in the Seventh Letter that some of the Thirty were actually close connexions and acquaintances of his (oikeioi te kai gnȏrimoi, 324d1-2). And so it is likely that Plato was acquainted with Parmenides’ arguments against Socrates’ theory of Forms yet before his half-brother Antiphon began to learn them by heart. As the dialogue suggests, Parmenides’ criticism left Socrates in the state of a self-reflected philosophic ignorance, which a philosophically minded young man could not find very attractive.
What Diogenes says in 3. 5-6 is the following: ‘At first Plato used to study philosophy in the Academy, and afterwards in the garden at Colonus, as a follower of Heraclitus. Afterwards, when he was about to compete for the prize with a tragedy, he listened to Socrates in front of the theatre of Dionysius, and then consigned his poems to the flames, with the words ‘Come hither, O fire-god, Plato now has need of thee.’ From that time onward, having reached his twentieth year (so it is said), he was the pupil of Socrates.’ This does not mean ‘that Plato knew Socrates only from the age of twenty’; it means that at the age of twenty Plato had a dramatic philosophic encounter with Socrates as a result of which he not only burnt the tragedy with which he was about to compete, but ceased to be a follower of Heraclitus and became a disciple of Socrates.
Aristotle informs us that Plato, who in his youth became a Heraclitean, believing that all sensible things are in constant flux and there is no knowledge about them, encountered Socrates who fixed his mind (brought his mind to a standstill) on definitions of moral concepts (peri horismȏn epistêsantos tên dianoian), and that because of this – that is because he saw that Socrates brought his mind to a standstill, fixed on the definitions of moral concepts – he conceived (hupelaben) that this must have been happening concerning different things (hȏs peri heterȏn touto gignomenon), things that are different from sensible things (ou tȏn aisthêtȏn): ‘this kind of beings he called Forms’ (ta men toiauta tȏn ontȏn ideas prosêgoreuse). (Arist. Met. A, 987a32-b8).
In the Parmenides 128e6-129a6 Socrates challenges Zeno and Parmenides with a theory of Forms: ‘Do you not acknowledge that there exists, alone by itself, a certain Form of similarity, and another which is opposite to it, which is dissimilar; and that you and I and the other things we call many get a share of these two things. And that things that get a share of similarity become similar in the respect and to the degree that they get a share; things that get a share of dissimilarity become dissimilar, and that things that get a share of both become both?’ – Socrates’ eyes are directed at things that have a similar form, which leads him to suppose that there must be a single Form, in which they all get a share. It is this derivation of the Forms from things around on which Parmenides bases his criticism: ‘I think that the reason why you think that each Form is one is like this: When many things appear to you to be large, there perhaps seems to be some Form, which is one and the same, as you look on them all; whence you believe the large is one’. Socrates: ‘True’. (132a1-5)
As Aristotle indicates, Plato arrived at the Forms in a very different way, by conceiving the Forms to which Socrates’ fixation of mind on definitions pointed. Republic V, where Plato introduces the Forms, corroborates Aristotle’s testimony. At 473c-e Socrates proclaims that only philosophers can govern a state properly. Challenged by Glaucon to justify his pronouncement, Socrates defines philosophers as those who can see the truth and love seeing it (tous tês alêtheias philotheamonas). When Glaucon asks, what he means by it, Socrates explains: ‘Since beauty is the opposite of ugliness, they are two? – And inasmuch as they are two, each of them is one? – And of just and unjust, good and evil, and of every other Form, the same mark holds: taken singly, each of them is one; but from the various combinations of them with actions and bodies and with one another (têi de tȏn praxeȏn kai sȏmatȏn kai allêlȏn koinȏniai), they are seen in all sorts of lights and appear many (pantachou phantazomena polla phainesthai hekaston)? – And this is the distinction which I draw between the sight-loving (philotheamonas), art-loving (philotechnous), practical class (praktikous) which you have mentioned, and those of whom I am speaking, and who are alone worthy of the name of philosophers. – The lovers of sounds and sights are fond of fine tones and colours and forms and all the artificial products that are made out of them, but their mind is incapable of seeing or loving absolute beauty (autou de tou kalou adunatos autȏn hê dianoia tên phusin idein te kai aspasasthai). – Few are they who are able to attain to this ideal beauty and contemplate it.’ (475e4-476b11, tr. Jowett)
In the Parmenides, after finishing his exposition of the greatest difficulty concerning the Forms, Parmenides reflects on the whole preceding discussion concerning the Forms: ‘These, and many other difficulties on top of these, necessarily pertain to the Forms, if these Forms of beings exist (ei eisin hautai hai ideai tȏn ontȏn), and if one is going to define each Form itself. The result is that the hearer is perplexed and contends that they do not exist, and that even if their existence is conceded, they are necessarily unknowable by human nature. In saying this, he seems to be saying something (dokein te ti legein) and, as we just remarked, it’s astonishingly hard to convince him to the contrary. Only a man of considerable natural gifts will be able to learn that there is a certain kind of each thing (hȏs esti ti genos hekastou), being that is alone by itself (ousia autê kath’ hautên), and it will take a man more remarkable still to discover it (eti de thaumastoterou tou heurêsontos) and be able to instruct someone else (kai allon dunêsomenou didaxai) who has examined all these difficulties with sufficient care (tauta panta hikanȏs dieukrinêsamenon).’ (134e9-135b2)
Allen remarks: ‘It will be observed that Parmenides does not suppose that the arguments against participation cannot be solved. He rather supposes they can be solved, but that it will take a man of remarkable gifts to solve them. It is evident from this single passage that Parmenides does not suppose that his criticisms of the theory of Ideas are a mere tissue of fallacies. On the contrary, they are deep and serious, and raise difficulties that must be thought through if the theory of Ideas is to be sustained. Socrates, young and inexperienced, has not yet thought them through with sufficient care.’ (R. E. Allen, ‘Comment’, in Plato’s Parmenides, Yale University Press, 1997, p. 203)
As I have noted in ‘Allen’s misrepresentation of Plato’s Parmenides’ (posted on November 12, 2015), nothing in what Parmenides said suggests that he supposes ‘that his criticisms, and many other difficulties on top of these’ (134e9-135a1) can be solved. On the contrary, he maintains that these difficulties ‘necessarily pertain to the Forms’ (135a1), and yet he views all these criticisms of the theory of Ideas as false. When he says that a man who voices such criticisms ‘seems to be saying something’ (dokein ti legein), he implies that ‘he is saying nothing’ (ouden legei).
In the Parmenides itself the criticisms that Parmenides had raised against the Forms are thus viewed as irrelevant to a person who finds the Forms. But Parmenides’ words ‘as we just remarked’ (135a6) refer to his words ‘one could not show to the objector that he is saying a falsity (hoti pseudetai), unless he happened to be a man of great experience and natural ability, willing to follow a man who would show him the Forms in the course of a copious and lengthy undertaking .’ (133b6-9) The words ‘willing to follow a man who would show him the Forms in the course of a copious and lengthy undertaking’ take us to the Republic.
In Republic II to IV Socrates constructs a proto-ideal state and by inspecting its composition consisting of three main classes, labourers, soldiers, and the wise guardians, he discovers the four cardinal virtues, courage, wisdom, temperance and justice. He then finds analogous three parts in the human soul and in it the corresponding virtues. On that occasion he remarks: ‘I must impress upon you, Glaucon, that in my opinion our present methods of argument are not at all adequate to the accurate solution of this question: the true method is another and longer one (435c9-d3).’ It is only in Book VI that Socrates gets to the point at which he can outline the true method; he tells Adeimantus: ‘You may remember that we divided the soul into three parts; and by relating them to each other, distinguished the several natures of justice, temperance, courage, and wisdom? … We were saying that he who wanted to see them in their perfect beauty must take a longer and more circuitous way, at the end of which they would appear … the guardian of the State must be required to take the longer circuit or he will never arrive at the highest knowledge which most belongs to him.’ (504a4-d3, tr. Jowett)
This longer road leads to the Form of the Good (tên tou agathou idean) ‘which imparts truth to the known and the power of knowing to the knower’ (to tên alêtheian parechon tois gignȏskomenois kai tȏi gignȏskonti tên dunamin parechon, 508e1-3). ‘The good not only infuses the power of being known into all things known, but also bestow upon them their being and existence, and yet the good is not existence, but lies far beyond it in dignity and power.’ (509b6-10) ‘All things known’ are here the Forms, for only the Forms can be known. All things perceived by our senses are the province of mere opinion, they have no true being, they belong to the sphere that is intermediary between being and not-being: ‘The many notions which the multitude entertain about the beautiful and about all other things are tossing about in some region which is half-way between pure being and pure not-being’ (479d3-5, tr. Jowett). It is from within this region that for Plato of the Republic all objections against the Forms are derived; this is why they merely ‘appear to say something’ from the point of view of Plato in the Parmenides (135a6).
When we realize that Plato dramatically staged the Parmenides so as to direct the reader’s mind towards the Republic, we can appreciate the significance of Adeimantus’ brief characterization of Antiphon ‘when Antiphon was young, he diligently and thoroughly rehearsed (eu mala diemeletêse) the arguments, though now, like his grandfather of the same name, he spends most of his time on horses’. As a youngster, Antiphon delighted in arguments against the Forms: ‘Youngsters, when they first get the taste for arguments, they argue for amusement, always using arguments to effect contradiction (aei eis antilogian chrȏmenoi)’, Socrates points out to Glaucon in Republic 539b2-5. Such spiritual nourishment could not generate in Antiphon a lasting commitment to philosophy; those, whose mind is turned to real philosophy, become committed to it and delight in it the more the older they get.