Ancient History & Civilisation


The philosophical passages in the Republic are of first importance for the understanding of Plato’s philosophy. The three best known, the similes of the Sun, the Divided Line and the Cave, run consecutively, and we are explicitly told to connect the third of them, the Cave, with ‘what has preceded it’ (517b , Part VII, note 78). I have suggested (Part VII, section 5(2)) that this phrase must be interpreted to cover also the philosophical passages which occur earlier in Part VII and especially in section 2(1). In addition, the section on Dialectic in Part VIII (section 3: cf. note 23) explicitly refers back to the Cave and Line and seems to be intended as a summary of the philosophical teaching of the dialogue.

It is not easy to keep all these passages in mind at once, and the table on the following pages is intended to set them out visually together in skeleton form, in the belief that the first step to understanding them is to study them together. The horizontal divisions do not reproduce the proportions of the Line, partly for typographical reasons and partly because their significance is still a matter of argument. Plato can hardly have failed to notice that sub-section B = sub-section C; but we are given no hint of what this may mean, though we are warned not to embark on interpretations beyond those we are given for fear of landing ourselves in a long argument (534 (a) , and Part VIII, note 23). The main horizontal division in the table is that between knowledge and the operations of the intellect or intelligence on the one hand and ‘opinion’ on the other, with the corresponding fields or realms of reality which they apprehend. The four sub-divisions in the Line refer to mental operations and do not necessarily recur in the fields corresponding to them.Noēsis and dianoia seem to be two ways of dealing with forms and not to correspond to two different types of ‘object’ apprehended; pistis and eikasia do in a sense correspond to a difference of object, but the ‘objects’ of eikasia can have no independent existence from those of pistis , of which they are derivations (shadows, reflections). The sub-divisions are not therefore always easy to trace when not explicitly referred to, and we might doubt their importance but for their emphatic final reappearance (534 (a) ), after references to the Cave (532 (b)) and Line (533 (c) ), in the Educational programme (531 (d) ff.).

The Good appears regularly as the culmination of the scheme and is shown at the head of the vertical columns in italics to indicate its pre-eminence.

In Col. III i.C the phrase ‘Commonsense assurance’ as a rendering of pistis is taken from Cross and Woozley.

The last entries in Col. III i.D and Col. V i.D are bracketed because they are an interpretation and not a direct reference to anything Plato says, though Col. IV 2 (last entry) provides some justification for them (cf. Cross and Woozley, pp. 220–21).

‘Mathematical Objects’ in Col. III 2 are shown in brackets because there seems to be no direct reference to them in the text and most commentators think they had no place in this stage of Plato’s thought.

What the table does bring out, I hope, is that Plato does not, at each stage, mention all the details of his philosophy; Col. I, for example, has only a single horizontal division, and as already mentioned, the fourfold division occurs irregularly after its introduction. On the other hand, when all the passages are considered together a reasonably consistent pattern emerges, even if details remain uncertain.

In these passages in the Republic the emphasis is largely intellectual. There is a long training in the disciplines of mathematics and of ‘dialectic’, which comprises what we should call logic and philosophy. But Socrates has hinted (506 (d)) that the apprehension of the Form of the Good, the final objective of the philosophic process, is something of which it is difficult to give a direct description, and has substituted (507 (a)–521 (a)) the three similes of Sun, Line and Cave. We find a less intellectual approach in the Phaedrusand Symposium (translations of both which dialogues are available in Penguin). It has been called by Simone Weil the way of salvation through feeling. In the Phaedrus the soul again has three parts or elements (cf. Part V, section 2 ff. above), and is compared to a winged chariot with two horses and a driver; there is a good horse corresponding to thethumoeides of the Republic , an unruly horse corresponding to the Republic’s ‘appetite’, and a driver, the Republic’s reason. The soul is immortal and in its disembodied state joins at one point a great procession and sees ‘what is outside the heavens’ (247 (b) ), the whole realm of the Forms, of which it retains some recollection which may be awakened by its perceptions when it is embodied in this life, in particular by perceptions of beauty. (Compare the myth of Er in the Republic , Part XI, section 3.) The same thought recurs in the Symposium , where the driving force is Éros , the love of beauty in all forms and the impulse to all creative activity, ranging from its simplest form in physical reproduction to its higher levels in artistic and literary creation, and culminating in philosophy. The process is described by Socrates in the form of an account which he says was given to him by a ‘wise woman’, a priestess called Diotima. The culmination of the process is a final vision or revelation, and Diotima describes the way to it as follows:

‘“Anyone who wants to pursue this goal correctly must begin by turning to physical beauty, and then if he gets the right guidance fall in love with a particular individual and with him produce thoughts of beauty. He must then perceive that the beauty in one individual is similar to that in another, and that if beauty of form is what he is pursuing it is stupid not to recognize that the beauty exhibited by all individuals is the same. With that recognition he becomes the lover of all physical beauty, and his passion for a single individual slackens as something of small account. The next stage is for him to reckon beauty of mind more valuable than beauty of body, and if he meets someone who has an attractive mind but little bodily charm, to be content to love and care for him and produce thoughts which improve the young; this again will compel him to look for beauty in habits of life and customs and to recognize that here again all beauty is akin, and that bodily beauty is a poor thing in comparison. From ways of life he must proceed to forms of knowledge and see their beauty too, and look to the fullness of beauty as a whole, giving up the slavish and small-minded devotion to individual examples, whether a boy or man or way of life, and turning instead to the great sea of beauty now before his eyes. He can then in his generous philosophic love beget great and beautiful words and thoughts, and be strengthened to glimpse the one supreme form of knowledge, whose object is the beauty of which I will now speak… For anyone who has been guided so far in his pursuit of love, and surveyed these beauties in right and due order, will at this final stage of love suddenly have revealed to him a beauty whose nature is marvellous indeed, which is the culmination of all his efforts.”’ (210 ae )

The conception of an intelligible realm beyond the range of ordinary sense-perception and yet in some way dependent on it which we find in the Republic fits in well with the higher realm of the Phaedrus and Symposium . In them the supreme Form is beauty; in the Republic it is the good. ThePhaedrus and Symposium add passion and feeling to the more intellectual austerity of the Republic , but the personal experience in which both processes culminate is something which eludes exact verbal expression and Plato has to resort to simile and myth.

Col. I The philosopher,
knowledge & reality

II The Sun

III The Line

1. Cognitive state

2. Field of operation


1. State of mind (pathēma 511d)

2. Field of Operation

Knowledge: epistēmē, 477b or gnōsis, 477a

Infallible 477e

The forms (idea 479a eidos 476a); each single 476a. Beauty itself, justice itself, etc. 476a.
What is, being (to on, ousia 478a, 479c)

cf. 485b eternal reality

The form of the good 508e

Beauty itself etc.507b apprehended by intelligence and knowledge (nous, gnōsis 508d)

The good is source of being, reality and intelligibility (b, 508d)

Knowledge: epistēmē

A. Intelligence A. (noēsis, nous) Upward movement to a first principle (archē) thence back to conclusions (a, b). Deals with forms only emē(c)

B. Reasoning B. (dianoia) Downward movement from assumptions to conclusion, as in geometry and kindred technai (511a, b, d). Uses visible figures as illustrations (510d–e, 511a)

Intelligible realm (noētos topos509d)

The first principle (archē) of everything (511a, b)

A. The forms 511c

B. Mathematical postulates etc. 510c–511b (Mathematical objects?526a)

Opinion: doxa, 477bIntermediate between epistēmē & agnoia

Fallible, 477e


Agnoia 477b, 478c agnōsia477a

The multiplicity of actions, objects, things: 476a, 476c, 479e. These ‘share in’ (metechein) the corresponding form. They are subject to change (485b) and ‘hover between being and not-being’479a–d

What is not (to mē on 478c, 479c)

The visible sun

Particular beautiful etc. things (507b). The twilight world of change (coming-to-be: genesis) apprehended by opinion (doxa): 508d

The sun is cause of coming-to-be and growth as well as of visibility (b)

Opinion: doxa

C. Belief C. (pistis): 511de. ‘Commonsense assurance’

D. Illusion D. (eikasia): 511de (Sophist, poet, artist: cf. Part X)

Visible realm (borātos topos 509d)

C. Animals, plants, manufactured objects (a)

Models or drawings of geometrical figures510d–e

D. Images, shadows, reflections of originals in C (510a)

1. Simile

2. Interpretation

1. Activity

2. Field of operation

3. Summary (533e534a)

The Sun (516b)

A. Real physical things (ab)

B. Shadows and reflections of real things (516a)

outside the Cave

The Good 517bc

The education of the philosopher (the upward progress of the mind517b)

A. Dialectic (d) which completes the philosopher's studies (532a, 534e)

B. The five mathematical studies, corresponding to the escape from the cave and looking at shadows and reflections (532bc)

The form of the good (526d, 534c)

The intelligible realm (noēton 524c); eternal and unchanging (527b)


A. Knowledge (epistēmē)

B. Reasoning (dianoia)

The fire (514b)

C. Artificial models of real things in A (514c: cf. 517d images, 532blikenesses)

D. Shadows thrown by the models in C, or echoes caused by their carriers (515ab)

inside the Cave

The visible realm 517ab

C. Images of justice (517d)

D. Shadows of these images (517d)

C. The first stage of education (521e–522a)

(D. cf. The misleading activities of sophist, poet, artist)

The visible realm (borāton), subject to change (genesis):524c,527b


C. Belief (pistis)

D. Illusion (eikasia)

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