Having defined philosophers as those who can see the Forms, and distinguished them from those who can’t, Socrates in Republic V proceeds to define the faculty that belongs to the former and the faculty that belongs to the latter: ‘He who, having a sense of beautiful things (Ho oun kala men pragmata nomizȏn), has no sense of absolute beauty (auto de kallos mête nomizȏn), or who, if another lead him to a knowledge of that beauty, is unable to follow (mête, an tis hêgêtai epi tên gnȏsin autou, dunamenos hepesthai) – of such a one I ask, Is he awake or in a dream only (onar ê hupar dokei soi zên;)? Reflect (skopei de): is not the dreamer, sleeping or waking, one who likens dissimilar things, who puts the copy in the place of the real object (to oneirȏttein ara ou tode estin, eante en hupnȏi tis eant’ egrêgorȏs to homoion tȏi mê homoion all’ auto hêgêtai einai hȏi eoiken;)?’ – Glaucon: ‘I should certainly say (Egȏ g’oun an phaiên) that such a one was dreaming (oneirȏttein ton toiouton).’ – Soc. ‘But he who, on the contrary (Ti de; ho t’anantia toutȏn), recognizes the existence of absolute beauty (hêgoumenos te ti auto kalon) and is able to contemplate (kai dunamenos kathoran ‘and is able to see distinctly’) both the Idea (kai auto) and the objects which participate in it (kai ta ekeinou metechonta), neither putting the objects in the place of the Idea nor the Idea in the place of the objects (kai oute ta metechonta auto oute auto ta metechonta hêgoumenos) – is he a dreamer, or is he awake (hupar ê onar au kai houtos dokei soi zên;)?’ – Glauc. ‘He is wide awake (Kai mala hupar).’ – Soc. ‘And since he knows, it would be right to describe his state of mind as knowledge (Oukoun toutou men tên dianoian hȏs gignȏskontos gnȏmên an orthȏs phaimen einai), and the state of mind of the other, who opines only, as opinion (tou de doxan hȏs doxazontos;)?’ – Glauc. ‘Certainly (Panu men oun).’ (476c2-d7, tr. Jowett)
After defining the state of mind of the true philosopher as knowledge (gnȏmê), the state of mind of those who can’t see the Forms as opinion (doxa), Socrates outlined the realms within which these two faculties operate: ‘Does he who has knowledge know something or nothing (ho gignȏskȏn gignȏskei ti ê ouden;)?’ – Glaucon: ‘He knows something (gignȏskei ti).’ – Soc. ‘Something that is or is not (Poteron on ê ouk on;)?’ – Glauc. ‘Something that is (On); for how can that which is not ever be known (pȏs gar an mê on ge ti gnȏstheiê)?’ – Soc. ‘And are we assured (Hikanȏs oun touto echomen), after looking at the matter from many points of view (k’an ei pleonachêi skopoimen), that the fully real (hoti to men pantelȏs on) is or may be fully known (pantelȏs gnȏston), but that the utterly unreal (mê on de mêdamêi) is utterly unknown (pantêi agnȏston)?’ – Glauc. ‘Nothing can be more certain (Hikanȏtata).’ – Soc. ‘Good (Eien). But if there be anything which is of such a nature (ei de dê ti houtȏs echei) as to be and not to be (hȏs einai te kai mê einai), that will have a place intermediate (ou metaxu an keoito) between pure being (tou eilikrinȏs ontos) and the absolute negation of being (kai tou au mêdamêi ontos;)?’ – Glauc. ‘Yes, between them (Metaxu) (476e7-477a8) … Thus then we seem to have discovered (Hêurêkamen ara, hȏs eoiken,) that the many notions which the multitude entertains (hoti ta tȏn pollȏn polla nomima) about the beautiful and about all other things (kalou te peri kai tȏn allȏn) are tossing about in some region which is half-way between pure being and pure not-being (metaxu pou kulindeitai tou te mê ontos kai tou ontos eilikrinȏs).’ – Glauc. ‘We have (Hêurêkamen).’ – Soc. ‘Yes; and we have before agreed (Proȏmologêsamen de ge,) that anything of this kind which we might find (ei ti toiouton phaneiê) was to be described as matter of opinion, and not as matter of knowledge (doxaston auto all’ ou gnȏston dein legesthai,); being the intermediate flux which is caught and detained by the intermediate faculty (têi metaxu dunamei to metaxu planêton haliskomenon).’ – Glauc. ‘Quite true (Hȏmologêkamen).’ (479d3-10, tr. Jowett)
In Republic V Socrates discusses extensively the faculty of opinion-making as a wanderer in the fleeting realm that is intermediate between being and not being. He does so to turn the mind of his listeners (readers) to the realm of true being, of the Forms which are ‘absolute and eternal and immutable’ (auta hekasta kai aei kata t’auta hȏsautȏs echonta, 479e7-8, tr. Jowett). In Republic X Socrates proceeds in the opposite way; strange as it may sound, after he ascribed to the artisans the capacity to see the forms of the objects they are producing, he corrects himself, but he does not correct himself by depriving the artisans of the capacity to see the forms, he does so by abandoning the forms, thus finding ‘what is’, and the knowledge of it, in the realm that Socrates in Republic V deprived of true being and of knowledge.
Socrates: ‘Of the painter (Zȏgraphos) we say (phamen) that he will paint reins (hȇnias te graphei), and he will paint a bit (kai chalinon;)?’ – Glaucon: ‘Yes (Nai.).’ – ‘And the worker in leather and brass will make them (Poiȇsei de ge skutotomos kai chalkeus;)?’ – Glauc. ‘Certainly (Panu ge.).’ – Soc. ‘But does the painter know the right form of the bit and reins (Ar’ oun epaiei hoias dei tas hȇnias einai kai ton chalinon ho grapheus;)? Nay, hardly even the workers in brass and leather who make them (ȇ oud’ ho poiȇsas, ho te chalkeus kai ho skuteus,); only the horseman who knows how to use them – he knows their right form (all’ ekeinos hosper toutois epistatai chrȇsthai, monos ho hippikos;).’ (601c6-13, tr. Jowett)
An attentive reader may exclaim at this point: ‘You introduced this passage with the words “strange as it may sound, after he ascribed to the artisans the capacity to see the forms of the objects they are producing, he corrects himself, but he does not correct himself by depriving the artisans of the capacity to see the forms, he does so by abandoning the forms, thus finding what is and the knowledge of it in the realm, which Socrates in Republic V deprived of being and of knowledge”. Plato found you immediately to be wrong, for he deprives the artisans of the ability to see the forms only to ascribe it to the users of objects the artisans produce. It is not accidental that Plato chose “the bit and reins” as an example of the form of which only the horseman knows. He thus takes us in the right direction. Horsemen (hippȇs) were classed as arisocracy; only an aristocrat can see the forms of objects he uses, the artisans must obey his instructions.’
This comment is apposite, but it relies on Jowett, it has nothing to do with Plato’s text. Jowett’s ‘But does the painter know the right form of the bit and reins?’ stands for Socrates’ Ar’ oun epaiei hoias dei tas hȇnias einai kai ton chalinon ho grapheus;, which means ‘But does the painter know what the bit and reins are to be?’. Jowett’s ‘only the horseman who knows how to use them – he knows their right form’ stands for Socrates’ all’ ekeinos hosper toutois epistatai chrȇsthai, monos ho hippikos;, which means ‘but the one who knows how to use them, only the horseman’. Jowett’s ‘he knows their right form’ seriously misrepresents the text. It misrepresents the text so as to ‘iron out’ what Jowett perceives as a discrepancy between Republic X and Republic V-VII.