When a man cannot measure, and a great many others who cannot measure declare that he is four cubits high, can he help believing what they say?
Nay, he said, certainly not in that case.
Well, then, do not be angry with them; for are they not as good as a play, trying their hand at paltry reforms such as I was describing; they are always fancying that by legislation they will make an end of frauds in contracts, and the other rascalities which I was mentioning, not knowing that they are in reality cutting off the heads of a hydra?
Yes, he said; that is just what they are doing.
I conceive, I said, that the true legislator will not trouble himself with this class of enactments whether concerning laws or the constitution either in an ill-ordered or in a well-ordered State; for in the former they are quite useless, and in the latter there will be no difficulty in devising them; and many of them will naturally flow out of our previous regulations.
What, then, he said, is still remaining to us of the work of legislation?
Nothing to us, I replied; but to Apollo, the God of Delphi, there remains the ordering of the greatest and noblest and chiefest things of all.
Which are they?
he said.
The institution of temples and sacrifices, and the entire service of gods, demigods, and heroes; also the ordering of the repositories of the dead, and the rites which have to be observed by him who would propitiate the inhabitants of the world below.

These are matters of which we are ignorant ourselves, and as founders of a city we should be unwise in trusting them to any interpreter but our ancestral deity.

He is the god who sits in the center, on the navel of the earth, and he is the interpreter of religion to all mankind.
You are right, and we will do as you propose.
But where, amid all this, is justice?
son of Ariston, tell me where.
Now that our city has been made habitable, light a candle and search, and get your brother and Polemarchus and the rest of our friends to help, and let us see where in it we can discover justice and where injustice, and in what they differ from one another, and which of them the man who would be happy should have for his portion, whether seen or unseen by gods and men.
SOCRATES - GLAUCON Nonsense, said Glaucon: did you not promise to search yourself, saying that for you not to help justice in her need would be an impiety?
I do not deny that I said so, and as you remind me, I will be as good as my word; but you must join.
We will, he replied.
Well, then, I hope to make the discovery in this way: I mean to begin with the assumption that our State, if rightly ordered, is perfect.
That is most certain.
And being perfect, is therefore wise and valiant and temperate and just.
That is likewise clear.
And whichever of these qualities we find in the State, the one which is not found will be the residue?
Very good.
If there were four things, and we were searching for one of them, wherever it might be, the one sought for might be known to us from the first, and there would be no further trouble; or we might know the other three first, and then the fourth would clearly be the one left.
Very true, he said.
And is not a similar method to be pursued about the virtues, which are also four in number?
Clearly.
First among the virtues found in the State, wisdom comes into view, and in this I detect a certain peculiarity.
What is that?
The State which we have been describing is said to be wise as being good in counsel?
Very true.
And good counsel is clearly a kind of knowledge, for not by ignorance, but by knowledge, do men counsel well?
Clearly.
And the kinds of knowledge in a State are many and diverse?
Of course.
There is the knowledge of the carpenter; but is that the sort of knowledge which gives a city the title of wise and good in counsel?
Certainly not; that would only give a city the reputation of skill in carpentering.
Then a city is not to be called wise because possessing a knowledge which counsels for the best about wooden implements?
Certainly not.
Nor by reason of a knowledge which advises about brazen pots, I said, nor as possessing any other similar knowledge?
Not by reason of any of them, he said.
Nor yet by reason of a knowledge which cultivates the earth; that would give the city the name of agricultural?
Yes.
Well, I said, and is there any knowledge in our recently founded State among any of the citizens which advises, not about any particular thing in the State, but about the whole, and considers how a State can best deal with itself and with other States?
There certainly is.
And what is knowledge, and among whom is it found?
I asked.
It is the knowledge of the guardians, he replied, and found among those whom we were just now describing as perfect guardians.
And what is the name which the city derives from the possession of this sort of knowledge?
The name of good in counsel and truly wise.
And will there be in our city more of these true guardians or more smiths?
The smiths, he replied, will be far more numerous.
Will not the guardians be the smallest of all the classes who receive a name from the profession of some kind of knowledge?
Much the smallest.
And so by reason of the smallest part or class, and of the knowledge which resides in this presiding and ruling part of itself, the whole State, being thus constituted according to nature, will be wise; and this, which has the only knowledge worthy to be called wisdom, has been ordained by nature to be of all classes the least.
Most true.
Thus, then, I said, the nature and place in the State of one of the four virtues has somehow or other been discovered.
And, in my humble opinion, very satisfactorily discovered, he replied.
Again, I said, there is no difficulty in seeing the nature of courage; and in what part that quality resides which gives the name of courageous to the State.
How do you mean?
Why, I said, every one who calls any State courageous or cowardly, will be thinking of the part which fights and goes out to war on the State's behalf.
No one, he replied, would ever think of any other.
Certainly not.
The rest of the citizens may be courageous or may be cowardly but their courage or cowardice will not, as I conceive, have the effect of making the city either the one or the other.
The city will be courageous in virtue of a portion of herself which preserves under all circumstances that opinion about the nature of things to be feared and not to be feared in which our legislator educated them; and this is what you term courage.
I should like to hear what you are saying once more, for I do not think that I perfectly understand you.
I mean that courage is a kind of salvation.
Salvation of what?
Of the opinion respecting things to be feared, what they are and of what nature, which the law implants through education; and I mean by the words 'under all circumstances' to intimate that in pleasure or in pain, or under the influence of desire or fear, a man preserves, and does not lose this opinion.

Shall I give you an illustration?
If you please.
You know, I said, that dyers, when they want to dye wool for making the true sea-purple, begin by selecting their white colour first; this they prepare and dress with much care and pains, in order that the white ground may take the purple hue in full perfection.

The dyeing then proceeds; and whatever is dyed in this manner becomes a fast colour, and no washing either with lyes or without them can take away the bloom.