ledge and truth, splendid as they are. And just as it was right ! to think of light and sight as being like the sun, but wrong to so, ! think of them as being the sun itself, so here again it is right"
to think of knowledge and truth as being like the good, but ~.;, wrong to think of either of them as being the good, whose '~~.. position must be ranked still higher.' :~t;
, You are making it something of remarkable splendour if 'c
it is the source of knowledge and truth, and yet itself more ~!~,- splendid than they are. For I supposeyoll can't mean it to be ,c, pleasure?' he asked.
'A monstrous suggestion,' I replied. 'Let us pursue our
analogy further.' c
'Go on.' 1.1": -~:
'The sun, I think you will agree, not only makes the things [~ we see visible, but causes the processes of generation, growth and nourishment, without itself being such a process.'
'The good therefore may be said to be the source not
only of the intelligibility of the objects of knowledge, but
also of their being and reality; yet it is not itself that reality,
but is beyond it, and superior to it in dignity and power.'
'It really must be miraculously transcendent,' remarked, Glaucon to the general amusement.
'Now, don't blame me,' I protested; , it was you who made
me say what I thought about it.'
, Yes, and please go on. At any rate finish off the analogy
with the sun, if you haven't finished it..
'I've not nearly finished it.'
'Then go on and don't leave anything out.'
'I'm afraid I must leave a lot out,' I said. 'But I'll do my
best to get in everything I can in present circumstances.'
'Yes, please do.'
The analogy of the Divided Line is, Plato makes clear, a seqllSl to the JIm simile, its purpose being to illll.ftrate further the relation be- hveen the hvo orders of reality with which the SIm simile dealt. Btdit
does so from a particular point of view, that of the states of mi~ (pathemata: II Id,p. }16) in which we apprehend these two orders or realms. The purpose of the Line, therefore, is not, primarilY, to give a classification of objects. Both of the two states of mind cor- related with the intelligible realm deal with the same kind of object (the forms), thollgh each deals with them in a different w/?y,. and though in the physical world there is a difference between physical things and their shadows, that difference is used primarilY to illustrate
degrees of' truth' or genllineness in what is apprehended - we know"
very little about a thing if our knowledge is confined to shadows or images of it or, for that matter, to its superficial appearance. The simile m/?y be set out in the form of the table below. "
Broadly speaking, the mental states comprised hy the follf'"
(noesis) or A
(pistis) C Physical
Opinion things
Illusion D Shadows and
(eikasia) images
-~. .". J-IO  
subdivisions are: (A) Intelligence. Full understanding, culminating in the vision of ultimate truth. This understanding is reached by philosophy, or as Plato often calls it 'dialectic'; a term Wholl modern associations are quite misleading in interpreting the Republic, but which, with that caution, remains a convenient translation. ( B) Reason. The procedure of mathematics, purefy deductive and uncritical of its assumptions. ( C) Belie}: Common- sense beliefs on matters both moral and physical, which are a fair practical guide to life but have not been fully thought out. (Later, in the Timaeus, Plato includes the natural sciences in this sub- section, as they can never reach ultimate trJlth, being concerned with a changeable world.) ( D) Illusion. All the various illusions, 'secondhand impressions and oPinions',I of which the minds of ordinary people are full. In this section 'illusion' merely appears as the perception of shadows and reflections. But the wider interpre- tation is demanded by the Cave simile, which elaborates in a more graphic form the classification set out in the Line. And it is also clearly implied in Book X (p. 42I below) that all works of poetry and art are to be inclllded in this sub-section.
To look forward for a moment, Plato is not entirely consistent ill his use of terms (see note 2,P.344). In Part VII§z..I (Pp. 267 if.) the contrast is frequently between doxa and gnosis, another word for knowledge. Noesis is sometimes used of sub-section A of the Line, but, perhaps because the content of the whole 'region' AB is called noeton, it is also used of intellectual operations more generally.
And at one place (P.344) episteme is used of subsection A.
The content of CD, commonly referred to in the Line as to horaton, the visible, is in this diagram also called the physical world. Though there is an emphasis in the simile on purely visual terms, Plato instances animals, plants and manufactured objects as examples in subsection C, and for example a donkey eating hay in a barn is not a purely visual object. Besides, it is made quite clear in Part VIII that CD is the world perceived by our senses (aistheton), the world
of material change (genesis) . The diagram assumes that both
noesis and dianoia deal with forms and that dianoia has no separate type of object. It is sometimes claimed that Plato implies that ther" are special mathematical objects in subsection B; but his language at
I. J. E. Raven, C/assicalQuar/eriy (Jan.-April, 19S3), p. 18.
S Iod (p. J r J) suggests rather that the mathematicians deal with forms, but in a not fullY adequate way. See also p. JJJ, note r.
This brief dogmatic summary can hardlY do justice to the prob,o:
/ems raised by the Line and its two companion similes and to the controversies which they have occasioned. Some suggestions for further.
reading will be found in the bibliography (p. 466: see especial!j I Cross and WooZley, Chs. .9 and TO). But the reader should first ~ study what Plato himself has to say about the way in which the similes are to be interpreted and linked: see especiallY pp. J20-2r..
pp. J42-J, andcf. Appendix I.
d 'You must suppose, then,' I went on, 'that there are these
two powers' of which 1 have spoken, and that one of them.
is supreme over everything in the intelligible order or region, "
the other over everything in the visible region - I won't say in the physical universe or you will think I'm playing with words.2 At any rate you have before your mind these two orders3 of things, the visible and the intelligible?' ,..,
'Yes, I have.'
'Well, suppose you have a line divided into two unequal parts, and then divide the two parts again in the same
ratio,4 to represent the visible and intelligible orders. This ij 510 gives you, in terms of comparative clarity and obscurity, in ?f~
the visible order one sub-section of images (D): by" images" ~:
I mean first shadows, then reflections in water and other: close-grained, polished surfaces, and all that sort of thing, if I
I ' ~
you understand me.' -.
'I understand.'
'Let the other sub-section (C) stand for the objects which t;::" are the originals of the images - the animals around us, and ~~ every kind of plant and manufactured object.' ",'
I. The form of the good and the sun.
2. The Greek words for 'visible' and for 'physical universe' (OJ' more literally 'heaven') bear some resemblance to each other, and it
has been suggested that there was some connection between them.
3. Eido.r: a good example of Plato's non-technical use of the term, to mean 'kind', 'sort'. 'type' (as also at SIlO, 'type of thing'). The technical (theory of 'forms') use is a natural sequel because things of
a particular kind have a particular form. !Ji 4. See diagram on p. 310.
, ,t'2~
'Very good.' ,
'Would you be prepared to admit that these sections differ in that one is genuine, I one not, and that the relation of image to original is the same as that of the realm of opinion to that of knowledge?'
'I most certainly would.' .
'Then consider next how the intelligible part of the line { { is to be divided.' Ii
'In one sub-section (B) the mind uses the originals of the I
visible order in their turn as images, and has to base its inquiries on assumptionsz and proceed from them not to a first principle but to a conclusion: in the other (A) it moves3 from assumption to a first principle which involves no assumption, without the images used in the other sub-
section, but pursuing its inquiry solely by and through forms I
themselves.' !
'I don't quite understand.' t
'I will try again, and what I have just said will help you to , understand. I think you know that students of geometry and calculation and the like begin by assuming there are odd and even numbers, geometrical figures and the three forms of
angle, and other kindred items in their respective subjects; , these they regard as known, having put them forward as t
basic assumptions which it is quite unnecessary to explain to themselves or anyone else on the grounds that they are
obvious to everyone. Starting from them, they proceed .. through a series of consistent steps to the conclusion which
they set out to ,find.' ~ "
'Yes, I certaInly know that.' ;, 'You know too that they make use of and argue about .",..
visible figures,4 though they are not really thinking about them, but about the originals which they resemble; it is not :
I, Lit: true,
2. Greek hypothesis, of which the English 'hypothesis' is a translitera- :, tion, But the English word means' something that may be true but needs' testing': the Greek word 'something assumed for the purpose of argu- ;, ment',
3. 5IOb6, omit TO.
4. Eidos, non-teclU1ical again.
about the square or diagonal which they have drawn that they are arguing, but about the square itself or diagonal itself, or whatever the figure may be, The actual figures they draw or model, which themselves cast their shadows and reflections in water - these they treat as images only, the real objects of their investigation being invisible except to
SII the eye of reason,'I
'That is quite true,'
'This type of thing 1 called intelligible, but said that the mind was forced to use assumptions in investigating it, and did not proceed to a first principle, being unable to depart from and rise above its assumptions; but it used as illustra- tions the very things (C) which in turn have their images and shadows on the lower level (D), in comparison with which they are themselves respected and valued for their clarity.'
b '1 understand,' he said, 'You are referring to what happens in geometry and kindred sciences.'2
'Then when 1 speak of the other sub-section of the intel- ligible part of the line you will understand that 1 mean that which the very process of argument grasps by the power of dialectic; it treats assumptions not as principles, but as assumptions in the true sense, that is, as starting points and steps in the ascent to something which involves no assump- tion and is the first principle of everything; when it has grasped that principle it can again descend, by keeping to the consequences that tollow from it, to a conclusion, The whole procedure involves nothing in the sensibl~world, but
,. moves solely through forms to forms, and finishes with forms.'
'I understand,' he said; 'though not fully, because what
I. The translation is intended to bring out the strong visual metaphor. More literally, 'seeking to see those very things that one cannot see except with the reason', The word translated 'reason' (dianoia) will be appropriated later in the passage as a quasi-teclU1ical term to designate the mathematical reasoning of sub-section B, ' As images': as we might say 'as illustrations',
2, Techne: see note 2, p, 315,
you describe sounds like a long job. But you want to dis- "i i.
tinguish that part (A) of the real and intelligible (A+B) which is studied by the sciencel of dialectic as having greater clarity than that (B) studied by what are called "sciences ".2 These sciences treat their assumptions as first principles and, though compelled to use reason3 and not sense-perception in surveying4 their subject matter, because they proceed in
their investigations from assumptions and not to a first ..
principle, they do not, you think, exercise intelligence on it, even though with the aid of a first principle it is intel- ligible.s And I think that you call the habit of mind of geometers and the like reason but not intelligence, meaning
t. Epi.rtimi: see note t, p. 83.
2. Lit: 'the so-called teGhnai'. The wide range of meaning of teGhni was noted on p. 73. Here the reference is to sub-section B of the line, and teGhni has already (note 2, p. 314) been used in the phrase 'geometry and kindred teGhnoi', which describes its contents. Plato certainly does not mean the arts or practical skills (d. p. 327), and Adam's 'mathe- matical sciences' gets the reference right. For more detail see Part VIII, pp. 331 ff, where d. note 4, p. 342.
3. Dionoio.
4. A strongly visual word - 'gazing at'. So also the word translated 'studied' has a basic meaning 'looked at', 'contemplated'.
5. Plato uses' intelligible' to describe the whole section A + B, which is the 'intelligible order' or 'region'. But here he seems to be referring to sub-section A only and to be indicating the deficiency of sub-section B, which is none the less dealing with material which if rightly handled is 'intelligible' in the full (A) sense. The meaning of the phrase is, however, uncertain. It reads literally 'it is intelligible (noiton) with (with the aid of? in conjunction with?) a (first) principle' or 'and has a first principle'. The interpretation here suggested gives a particular meaning to this more general wording: cf. again p. 342, note 4.
It is worth adding that, at 5110 and 5 I Ie, Plato emphasizes degrees of ,., G/arify, linked at 5IIe with truth; and that his four 'states' or 'habits' "
of mind are said to entail different degrees of clariry and truthfulness of apprehension, which need not correspond to a difference of object. Both shadow and object throwing it are in a sense physical things; it is our fault if we confuse them. If we speak of shadow and reflection as less true or genuine than their original this is really a comment on our own tendency to misapprehend them. Similarly, here, the mathematician has, compared to the philosopher, a defective apprehension of the same realities (the forms).
~:' 31"<-
by reason something midway between opinion (C+D) and intelligence (A).'
'You have understood me very well,' I said. 'So please take it that there are, corresponding to the four sections of the line, these four states of mind; to the top section intel-
e ligence, to the second reason, to the third belief, and to the
last illusion. I And you may arrange them in a scale, and
assume that they have degrees of clarity corresponding to the degree of truth possessed by their subject-matter.'
'I understand,' he replied, 'and agree with your proposed arrangement.'
This is a more graphic presentation of the truths presented in the analogy of the Line,' in particular, it tells us more about the two states of mind called in the Line analogy Belief and Illusion. We are shown the ascent of the mind from illusion to pure philosophy, and the dilficulties which accompany its progress. And the philosopher, when he has achieved the supreme vision, is required to return to the cave and serve his fellows, his very unwillingness to do so being his chief qualification.
As Cornford pointed out, the best way to understand the simile is to replace (the clumsier apparatus' of the cave by the cinema, though today television is an even better comparison. It is the moral and intellectual condition of the average man from which Plato starts,. and though clearly the ordinary man knows the difference between substance and shadow in the physical world, the simile suggests that his moral and intellectual opinions often bear as little relation to the truth as the average film or television programme does to real life.
I. The words used for 'belief' and 'illusion' do not (with the possible exception of a use of Pis/is in Book Xi see p. 4~0) occur elsewhere in Plato in the sense in which they are used here. Pis/is, 'belief', conveys overtones of assurance and trustworthiness: 'commonsense assurance' (Cross and Woozley, p. 226). Eikasia,' illusion', is a rare word whose few occurrences elsewhere in Greek literature give us little guidance. It can mean 'conjecture', 'guesswork', and some prefer so to translate it here. But 'illusion' is perhaps more appropriate for a 'state of mind '.