The Master of Trinity on the Platonic Theory of Ideas. 217 



theatre, which were divided again by the selis ; so that the spectators 

 would represent eleven banks of oars, seated, as in the trireme, with 

 the lower rows in advance. In the same way, the use of the sells in 

 a trireme, as the gangway for the officers, &c., explains the lines iu 

 the Agamemnon of .^Eschylus, 158S-9 : — 



(TV ruvra (poji-els reprepa Trpo/j{]f.iei'(is 

 KMin], i.pctTavvTwv Twy eiri ^vyt? copus ; 

 for if the zygitcE had been intended, tliey must have been described 

 as Tuv €wl ^vytSy. The same view of the o-eX/toro, as the proper 

 place for the officers, was used to explain another passage in the 

 same play (v. 1413), vvhere Agamemnon's companion is described as 

 ravTiKiLy creXj^u'iTiov iaroTpif3iis. And the risk of passing along these 

 planks, with intervals between them, was considered to explain the 

 proverbial warning that we must take care not to miss our footing 

 and fidl into the hold (Eurip. Heracl. 1G8). Other points were in- 

 cidentally noticed. 



Nov. 10. — The Master of Trinity read a paper " On the Platonic 

 Theory of Ideas." 



In this, he first stated the Platonic theory of ideas as given by the 

 late Professor Butler of Dublin, in his 'Lectures' (vol. ii. p. 117); he 

 then remarked that this theory had evidently, for one of its objects, 

 to explain the possibility of necessarJ^ and therefore eternal truths ; 

 and thus was an attemjit to solve the problem, often debated in 

 modern times, of the grounds of mathematical truth ; an attempt 

 especially called out by the Heraclitean skepticism of Plato's time. 

 'I'he doctrine of ideas which belong to the intelligible, not to the 

 visible toorld, and which are the basis of demonstration, did really 

 answer its purpose, and account for the existence of real and eternal 

 truths ; and at the same time, by the tenet that sensible things par- 

 ticipate in those ideas, accounted for the securing of truth respecting 

 the sensible world. But when Plato goes on to speak of ideas of 

 tables and chairs and the like, he gives an extension of the theory 

 •which solves no difficulty, and for which no valid reason is rendered. 



The arguments against this extension of the theory are given with 

 great force in the Dialogue entitled Parmenides, and are not answered 

 there, nor in a satisfactory way, in any part of Plato's writings. 

 Moreover, throughout this Dialogue, Parmenides is represented as 

 having, in his conversation with Socrates, vastly the superiority, not 

 only in argument, but in temper and manner ; and Socrates and his 

 friends, after a little show of resistance, assent submissively to all 

 that Parmenides says. On this ground the writer maintains that 

 the Dialogue is not Plato's, but anti-Platonic, written probably by an 

 admirer of Parmenides, and tending to represent Socrates and his 

 disciples as poor philosophers, conceited talkers, and feeble dis- 

 putants. 



This view was further confirmed by arguments drawn from the 

 external circumstances of the Dialogue. 



Nov. 24. — An account was given by Professor Miller, of the resto- 

 ration of the Standard of Weight {vide Phil. Mag. vol. xii. p. 540, 

 and p. 194 of the present volume. 



Phil. Mag. S. 4. Vol. 13. No. 85. March 1857. Q 



