Date of Plato’s birth

The extensive Wikipedia entry on Plato states in the section on ‘Plato’s birth and family’:

The exact time and place of Plato's birth are unknown. Based on ancient sources, most modern scholars believe that he was born in Athens or Aegina between 429 and 423 BC, not long after the start of the Peloponnesian War. The traditional date of Plato's birth during the 87th or 88th Olympiad, 428 or 427 BC, is based on a dubious interpretation of Diogenes Laërtius, who says, "When [Socrates] was gone, [Plato] joined Cratylus the Heracleitean and Hermogenes, who philosophized in the manner of Parmenides. Then, at twenty-eight, Hermodorus says, [Plato] went to Euclides in Megara." However, as Debra Nails argues, the text does not state that Plato left for Megara immediately after joining Cratylus and Hermogenes.^[24] In his Seventh Letter, Plato notes that his coming of age coincided with the taking of power by the Thirty, remarking, "But a youth under the age of twenty made himself a laughingstock if he attempted to enter the political arena." Thus, Nails dates Plato's birth to 424/423.^[25]

The author’s note 25 refers to Debra Nails’ The People of Plato, p. 246, where Nails says: ‘Plato makes his coming of age congruent with the ascendance of the Thirty. In one sense, Plato could be regarded as “coming of age” at eighteen since that is when he would be presented to the demesmen of Collytus, undergo scrutiny, and be registered as a citizen; he would begin military service by training and maintaining his gear, and would be expected to defend Attica within her borders. But a youth under the age of twenty made himself a laughingstock if he attempted to enter a political arena (Xen. Mem. 3,6). It thus appears that Plato is turning twenty as the Thirty take control of Athens; and that he does not immediately accept the invitation to join them is unexceptional, given his youth. Hence I date Plato’s birth 424/3.’

In these lines Nails interprets – or misinterprets – Plato’s Letter 7, 324b-d, which she quotes, presumably, in her own translation. The misinterpretation begins with her first sentence, for Plato does not ‘make his coming of age congruent with the ascendance of the Thirty’, he makes the ambition of his youth congruent with the ambition of other young men: ‘When I was a young man [ne/oj] I had the same ambition as many others: I thought of entering public life as soon as I came of age.’

Nails goes on to explain what was expected in Athens of a young man “coming of age” at eighteen: ‘he would begin military service’. Then she explains what a young man of eighteen was not supposed to do: ‘a youth under the age of twenty made himself a laughingstock if he attempted to enter a political arena’. Concerning this point, she refers to Xenophon’s Memorabilia 3,6.

Memorabilia 3,6 opens as follows: ‘Ariston’s son, Glaucon, was attempting to become an orator and striving for headship in the state, though he was less than twenty years old; and none of his friends or relations could check him, though he would get himself dragged from the platform and make himself a laughing-stock. Only Socrates, who took an interest in him for the sake of Plato and Glaucon’s [“the elder Glaucon”, a translator’s note] son Charmides, managed to check him.’ (Translation E.C. Marchant)

As can be seen, Xenophon refers to Plato’s brother Glaucon, who was making himself a laughingstock with his attempts to enter a political arena when he was less than twenty years old. Plato figures in the given passage, together with his uncle Charmides, as a man because of whom Socrates took interest in Glaucon, Plato’s younger brother.

To get some clarity to Nails’ misinterpretation of Plato’s Letter 7, 324b-d, let me put the passage as she quotes it, presumably in her own translation:

‘When I was a young man [ne/oj] I had the same ambition as many others: I thought of entering public life as soon as I came of age. And certain happenings in public affairs favoured me, as follows. The constitution we then had, being anathema to many, was overthrown; and a new government was set up consisting of fifty-one men, two groups – one of eleven and another of ten – to police the market place and perform other necessary duties in the city and the Piraeus respectively, and above them thirty other officers with absolute powers. Some of these men happened to be relatives and acquaintances of mine, and they invited me to join them at once in what seemed to be a proper undertaking.’

Let me stop Nails’ quotation of Plato’s Letter 7 at this point, for an attentive reader can’t help asking: ‘If Plato was eighteen at that time, as Nails supposes, how is it possible that his relatives and acquaintances invited him ‘to join them at once in what seemed to be a proper undertaking?’

This query applies to Nails’ quotation as it stands in her translation, but it becomes even stronger if we pay attention to the original. For Nails’ ‘to join them at once in what seemed to be a proper undertaking’ stands for Plato’s ‘kai\ dh\ kai\ pareka/loun  eu)qu\j w(j e0pi\ prosh/konta pra/gmata/ me. J. Harward translates: ‘and they at once invited me to share in their doings, as something to which I had a claim’. Nails in her translation failed to take notice of Plato’s self-reflective pronoun me, ‘me’ or ‘I’. R.G. Bury translates: ‘they invited me at once to join their administration, thinking it would be congenial’. If Plato was ‘a youth under the age of twenty’, as Nails supposes him to have been, how could ‘relatives and acquaintances of his’ invite him ‘to share in their doings, as something to which he had a claim’, as Harward puts it, or ‘to join their administration, thinking it would be congenial to him’, as Bury interprets Plato’s words?