So far am I from agreeing with Thrasymachus that justice is the interest of the stronger.

This latter question need not be further discussed at present; but when Thrasymachus says that the life of the unjust is more advantageous than that of the just, his new statement appears to me to be of a far more serious character.

Which of us has spoken truly?
And which sort of life, Glaucon, do you prefer?
I for my part deem the life of the just to be the more advantageous, he answered.
Did you hear all the advantages of the unjust which Thrasymachus was rehearsing?
Yes, I heard him, he replied, but he has not convinced me.
Then shall we try to find some way of convincing him, if we can, that he is saying what is not true?
Most certainly, he replied.
If, I said, he makes a set speech and we make another recounting all the advantages of being just, and he answers and we rejoin, there must be a numbering and measuring of the goods which are claimed on either side, and in the end we shall want judges to decide; but if we proceed in our enquiry as we lately did, by making admissions to one another, we shall unite the offices of judge and advocate in our own persons.
Very good, he said.
And which method do I understand you to prefer?
I said.
That which you propose.
Well, then, Thrasymachus, I said, suppose you begin at the beginning and answer me.

You say that perfect injustice is more gainful than perfect justice?
SOCRATES - GLAUCON - THRASYMACHUS Yes, that is what I say, and I have given you my reasons.
And what is your view about them?
Would you call one of them virtue and the other vice?
Certainly.
I suppose that you would call justice virtue and injustice vice?
What a charming notion! So likely too, seeing that I affirm injustice to be profitable and justice not.
What else then would you say?
The opposite, he replied.
And would you call justice vice?
No, I would rather say sublime simplicity.
Then would you call injustice malignity?
No; I would rather say discretion.
And do the unjust appear to you to be wise and good?
Yes, he said; at any rate those of them who are able to be perfectly unjust, and who have the power of subduing states and nations; but perhaps you imagine me to be talking of cutpurses.
Even this profession if undetected has advantages, though they are not to be compared with those of which I was just now speaking.
I do not think that I misapprehend your meaning, Thrasymachus, I replied; but still I cannot hear without amazement that you class injustice with wisdom and virtue, and justice with the opposite.
Certainly I do so class them.
Now, I said, you are on more substantial and almost unanswerable ground; for if the injustice which you were maintaining to be profitable had been admitted by you as by others to be vice and deformity, an answer might have been given to you on received principles; but now I perceive that you will call injustice honourable and strong, and to the unjust you will attribute all the qualities which were attributed by us before to the just, seeing that you do not hesitate to rank injustice with wisdom and virtue.
You have guessed most infallibly, he replied.
Then I certainly ought not to shrink from going through with the argument so long as I have reason to think that you, Thrasymachus, are speaking your real mind; for I do believe that you are now in earnest and are not amusing yourself at our expense.
I may be in earnest or not, but what is that to you ?--to refute the argument is your business.
Very true, I said; that is what I have to do: But will you be so good as answer yet one more question?
Does the just man try to gain any advantage over the just?
Far otherwise; if he did would not be the simple, amusing creature which he is.
And would he try to go beyond just action?
He would not.
And how would he regard the attempt to gain an advantage over the unjust; would that be considered by him as just or unjust?
He would think it just, and would try to gain the advantage; but he would not be able.
Whether he would or would not be able, I said, is not to the point.

My question is only whether the just man, while refusing to have more than another just man, would wish and claim to have more than the unjust?
Yes, he would.
And what of the unjust--does he claim to have more than the just man and to do more than is just.
Of course, he said, for he claims to have more than all men.
And the unjust man will strive and struggle to obtain more than the unjust man or action, in order that he may have more than all?
True.
We may put the matter thus, I said--the just does not desire more than his like but more than his unlike, whereas the unjust desires more than both his like and his unlike?
Nothing, he said, can be better than that statement.
And the unjust is good and wise, and the just is neither?
Good again, he said.
And is not the unjust like the wise and good and the just unlike them?
Of course, he said, he who is of a certain nature, is like those who are of a certain nature; he who is not, not.
Each of them, I said, is such as his like is?
Certainly, he replied.
Very good, Thrasymachus, I said; and now to take the case of the arts: you would admit that one man is a musician and another not a musician?
Yes.
And which is wise and which is foolish?
Clearly the musician is wise, and he who is not a musician is foolish.
And he is good in as far as he is wise, and bad in as far as he is foolish?
Yes.
And you would say the same sort of thing of the physician?
Yes.
And do you think, my excellent friend, that a musician when he adjusts the lyre would desire or claim to exceed or go beyond a musician in the tightening and loosening the strings?
I do not think that he would.
But he would claim to exceed the non-musician?
Of course.
And what would you say of the physician?
In prescribing meats and drinks would he wish to go beyond another physician or beyond the practice of medicine?
He would not.
But he would wish to go beyond the non-physician?
Yes.
And about knowledge and ignorance in general; see whether you think that any man who has knowledge ever would wish to have the choice of saying or doing more than another man who has knowledge.