In Republic V Plato’s Socrates explains ‘whom we mean when we dare to say that philosophers are to rule in the State’ (tous philosophous tinas legontes tolmȏmen phanai dein archein, 474b5-6). Glaucon asks: ‘Who then are the true philosophers (Tous de alȇthinous tinas legeis)?’ – Socrates: ‘Those who are lovers of the vision of truth (Tous tȇs alȇtheias philotheamonas).’ – Glaucon: ‘I should like to know what you mean (alla pȏs auto legeis)?’ – Soc. ‘To another I might have a difficulty in explaining (Oudamȏs raidiȏs pros ge allon); but I am sure that you will admit a proposition which I am about to make (se de oimai homologȇsein moi to toionde).’ – Glauc. ‘What is the proposition (To poion)?’ – ‘That since beauty is the opposite of ugliness (Epeidȇ estin enantion kalon aischrȏi), they are two (duo autȏ einai)?’ – Glauc. ‘Certainly (Pȏs d’ ou).’ – Soc. ‘And inasmuch as they are two (Oukoun epeidȇ duo), each of them is one (kai hen hekateron)?’ – Glauc. ‘True again (Kai touto).’ – Soc. ‘And of just (Kai peri dȇ dikaiou) and unjust (kai adikou), good (kai agathou) and evil (kai kakou), and of every other form (kai pantȏn tȏn eidȏn peri), the same remark holds (ho autos logos): taken singly, each of them is one (auto men hen hekaston einai); but from the various combinations of them with actions and bodies and with one another (tȇi de tȏn praxeȏn kai sȏmatȏn kai allȇlȏn koinȏniai), they are seen in all sorts of lights and appear many (pantachou phantazomena polla phainesthai hekaston).’ – Glauc. ‘Very true (Orthȏs legeis).’ – Soc. ‘And this is the distinction which I draw (Tautȇi toinun diairȏ) between the sight-loving, art-loving, practical class which you have mentioned (chȏris men hous nundȇ eleges philotheamonas te kai philotechnous kai praktikous), and those of whom I am speaking (kai chȏris au peri hȏn ho logos), and who are alone worthy of the name of philosophers (hous monous an tis orthȏs proseipoi philosophous).’ – Glauc. ‘How do you distinguish them (Pȏs legeis)?’ – Soc. ‘The lovers of sounds and sights are, as I conceive, fond of fine tunes and colours and forms and all the artificial products that are made of them (Hoi men oun philȇkooi kai philotheamones tas te kalas phȏnas aspazontai kai chroas kai schȇmata kai panta ta ek tȏn toioutȏn dȇmiourgoumena), but their mind is incapable of seeing or loving absolute beauty (autou de tou kalou adunatos autȏn hȇ dianoia tȇn phusin idein).’ – Glauc. ‘The fact is plain (Echei gar oun dȇ houtȏs).’ – Soc. ‘Few are they who are able to attain to this ideal beauty and contemplate it (Hoi de dȇ ep’ auto to kalon dunatoi ienai te kai horan kath’ hauto ou spanioi an eien;).’ – Glauc. ‘Very true (Kai mala).’ (475e4-476c1, tr. Jowett)
As can be seen, Glaucon is introduced to the Forms directly: since beauty is the opposite of ugliness, they are two, and inasmuch as they are two, each of them is one.
In Republic X Socrates investigates imitation (mimȇsis); he wants to know what it is (hoti pot’ estin, 595c7): ‘Well then, shall we begin the enquiry at this point (Boulei oun enthende arxȏmetha episkopountes), following our usual method (ek tȇs eiȏthuas methodou): Whenever a number of individuals have a common name, we assume that there is one corresponding idea or form (eidos gar pou ti hen hekaston eiȏthamen tithesthai peri hekasta ta polla, hois t’auton onoma epipheromen): – do you understand me (ȇ ou manthaneis)?’ – Glauc. ‘I do.’ (596a5-9)
R. M. Hare & D. A. Russell in their edition of Jowett’s translation are obviously unhappy with his translation of the last sentence, and they give what they think to be a better alternative: “[Or (probably better): we have been accustomed to assume that there is one single idea corresponding to each group of particulars: and to these we give the same name (as we give the idea),’ See J. A. Smith, C.R. xxxi (1917).]
Neither Smith nor Jowett properly expresses Socrates’ ‘positing one form (eidos ti hen tithesthai) in each case where to many particulars (peri hekasta ta polla ) we give one and the same name (hois t’auton onoma epipheromen)’.
Socrates goes on: ‘Let us take (Thȏmen), for our present purpose (dȇ kai nun), any instance of such a group (hoti boulei tȏn pollȏn); there are beds and tables in the world – many of each, are there not (hoion, ei theleis, pollai pou eisi klinai kai trapezai)?’ Glauc. ‘Yes (Pȏs d’ou;).’ – Soc. ‘But there are only two ideas or forms of such furniture (Alla ideai ge pou peri tauta ta skeuȇ duo) – one the idea of a bed (mia men klinȇs), the other of a table (mia de trapezȇs).’ – Glauc. ‘True (Nai).’ – Soc. ‘And the maker of either of them makes a bed or he makes a table for our use, in accordance with the idea – that is our way of speaking in this and similar instances (Oukoun kai eiȏthamen legein hoti ho dȇmiourgos hekaterou tou skeuous pros tȇn idean blepȏn houtȏ poiei ho men tas klinas, ho de tas trapezas, hais hȇmeis chrȏmetha, kai t’alla kata t’auta) – but no artificer makes the idea itself (ou gar pou tȇn ge idean autȇn dȇmiourgei oudeis tȏn dȇmiourgȏn): how could he (Pȏs gar;)? – Glauc. ‘Impossible (Oudamȏs).’ (596a10-b11, tr. Jowett)
When Socrates says in the tenth Book ‘we begin the enquiry following our usual method’ he is as far as he can be from Socrates whom Plato’s two brothers, Glaucon and Adeimantus, compelled in the second Book to overcome his philosophic ignorance and properly investigate the nature of justice. He is as far as can be from Socrates whom in the fifth Book Glaucon compels to go so far as to announce that ‘philosophers are to rule in the State’, if the state is to be governed well. The only justification for viewing philosophers as the only true rulers is that only they can see the Forms. The Forms a true philosopher can see are not Forms of the tenth Book, which are posited by Socrates on the basis of his observation that a number of individuals have a common name. The forms discussed by Socrates in the tenth Book are the forms with which the young Socrates challenged Zeno and Parmenides during they visit in Athens, the forms that Parmenides subjected to severe criticism, while assuring Socrates that if someone were not to allow the forms of things to be (ei ge tis mȇ easei eidȇ tȏn ontȏn einai) because of the difficulties which he had pointed out, and other such difficulties concerning them (eis panta ta nundȇ kai alla toiauta apoblepsas), he would completely destroy the power of discussion (houtȏs tȇn tou dialegesthai dunamin pantapasi diaphterei, Parm. 135b6-c2). Parmenides adds that it seems to him that Socrates is well aware of this (tou toioutou men oun moi dokeis kai mallon ȇisthȇsthai, 135c2-3).
The forms that Socrates posited following his usual method did not allow him to determine them ontologicaly as separate entities, but they allowed him to enter into discussion concerning them with anybody capable of seeing that there are countless instances, with which each of us is well acquainted, where many particular things have the same name because of their having the same characteristic. This allowed him to compel his interlocutors to admit that this common characteristic is something, and that it is something different from each of those things barring the same name, and thus to become involved in a discussion of ‘what it is’. Socrates found these enquiries fascinating, they led him to his theory of Reminiscence and thus opened to him a life-long span of daily philosophic activities. But these philosophic enquiries entitled neither him nor his interlocutors to think of themselves as natural ‘rulers of State’; by contrast, the Forms opened to the sight of Glaucon in the fifth Book of the Republic entitled the true philosophers to view themselves as such.