Book I, 335–341

335a but one who seems good without being good only seems to be a friend, and is not one. The same definition applies to an enemy.”“On this account, it seems, the good man will be a friend and the bad man an enemy.”“Yes.”“Do you ask us, then, to add to our account of justice? At first we said it was just to do good to a friend and harm to an enemy. Shall we now say, in addition, that it is just to do good to a friend who is good and to harm an enemy who is bad?” 335b“Certainly,” he said. “That would be well said, in my opinion.”“Then,” I asked, “is it the part of a just man to harm any human being at all?”“Of course,” he said. “The bad, who are his enemies, must be harmed.”“When horses are harmed, do they become better or worse?”“Worse.”“In the excellence proper to dogs, or in that proper to horses?”“In that proper to horses.”“And dogs, when harmed, become worse in the excellence proper to dogs, not to horses?”“They must.” 335c“And must we not say, my friend, that people who are harmed become worse in human excellence?”“Certainly.”“But is justice not a human excellence?”“That too is undeniable.”“Then people who are harmed, my friend, must become more unjust.”“So it seems.”“Can musicians use music to make people unmusical?”“Impossible.”“Can horsemen use horsemanship to make people unskilled with horses?”“No.”“Then can just men use justice to make people unjust? Or, 335d in general, can good men use excellence to make people bad?”“Impossible.”“For it is not the work of heat to cool things, I imagine, but of its opposite.”“Yes.”“Nor of dryness to moisten things, but of its opposite.”“Certainly.”“Nor, then, of the good to harm, but of its opposite.”“So it appears.”“And the just man is good?”“Certainly.”“So it is not the work of the just man, Polemarchus, to harm a friend or anyone else. It is the work of his opposite, the unjust man.”“I think you are entirely right, Socrates,” he said. 335e“Then if someone says justice is giving each person what is owed, and by that he means that a just man owes injury to enemies and benefits to friends, the man who said it was not wise. For what he said was untrue: we have found that it is never just to harm anyone.”“I agree,” he said.“Then you and I will fight together,” I said, “if anyone claims that Simonides, Bias, Pittacus, or any other wise and blessed man said it.”“I am ready, for my part,” he said, “to join in the fight.”

336a “But do you know,” I asked, “who I think is responsible for the saying that justice consists in benefiting friends and harming enemies?”“Who?” he asked.“I think it was Periander, or Perdiccas, or Xerxes, or Ismenias the Theban, or some other wealthy man who thought himself immensely powerful.”“What you say,” he replied, “is absolutely true.”“Very well,” I said. “Since justice and what is just have proved to be neither of these things, what else could one say justice is?” 336bSeveral times during our conversation Thrasymachus had begun to leap in and seize the argument, but the people sitting beside him restrained him because they wanted to hear it through. Once we had paused and I had spoken these last words, he could no longer keep quiet. Coiling himself like a wild beast, he sprang upon us as if to tear us apart.Polemarchus and I were startled out of our wits. Thrasymachus broke in before us: “What nonsense 336c has possessed you all this time, Socrates? Why do you play the fool together, bowing and scraping to each other? If you truly want to know what justice is, stop merely asking questions and seeking glory by refuting anyone who answers, knowing as you do that it is easier to ask than to answer. Give an answer yourself: say what you claim the just is. And do not tell me that it is 336d what is required, or beneficial, or profitable, or lucrative, or advantageous. Tell me clearly and precisely what you mean, because I will not accept such drivel from you.”I was stunned when I heard him, and looking at him I was afraid. I believe that if I had not looked at him before he looked at me, I would have lost my voice. But when he first began to grow savage at the course of the argument, I had looked at him first, 336e and so I was able to answer him. Trembling a little, I said, “Thrasymachus, do not be hard on us. If my friend and I go wrong in examining these arguments, you may be sure we do so unwillingly. Do not imagine that if we were searching for gold, we would willingly bow and scrape to each other in the search and ruin our chance of finding it, yet, when searching for justice—a thing worth far more than any quantity of gold—we would be so foolish as to give way to each other rather than make every effort to bring it to light. Surely you do not think so, my friend. I believe, rather, that we lack the power. It is much more fitting

337a for experts like you to pity us than to be angry.”At this he gave a harsh, derisive laugh and said, “By Heracles! Here is the usual irony of Socrates. I knew it, and I told these people in advance: you would refuse to answer, play the innocent, and do anything rather than answer a question.”“You are a wise man, Thrasymachus,” I said. “You knew perfectly well that if you asked someone what twelve is, and prefaced the question 337b by saying, ‘Mind you do not tell me, sir, that twelve is twice six, or three times four, or six times two, or four times three, because I will not accept such nonsense from you,’ no one would answer a question asked that way. But suppose he said to you, ‘Thrasymachus, what do you mean? Must I not give any of the answers you have forbidden? Even if one of them is true, my remarkable friend, am I to say something 337c other than the truth? Or what do you mean?’ What would you say in reply?”“Well!” he said. “As though the two cases were alike.”“Nothing prevents them from being so,” I said. “But even if they are not alike, and they seem so to the person questioned, do you think he will be any less likely to answer as it seems right to him, whether we forbid it or not?”“Is that what you will do, then?” he asked. “Will you give one of the answers I have forbidden?”“I would not be surprised,” I said, “if that is what I decide after considering the question.” 337d“And what if I show you an answer about justice different from all of these and better than they are? What penalty do you think you deserve?”“What else,” I said, “but the penalty appropriate to someone who does not know? Surely it is appropriate for him to learn from someone who does. That is the penalty I think I deserve.”“How charming,” he said. “But besides learning, you must pay me money.”“Once I have some,” I said.“But he does,” Glaucon said. “Speak, Thrasymachus, if money is the issue: all of us will pay for Socrates.” 337e“Oh yes, I am sure,” he said. “Then Socrates can do what he always does: give no answer himself, but catch hold of someone else’s answer and refute it.”“How could anyone answer, my good man,” I said, “when, first, he does not know and does not claim to know, and, second, even if he has an opinion, a man of no mean ability has forbidden him to say anything he thinks? It is far more fitting that you should speak: you claim to know and to have an answer.

338a Please do not refuse, but do me the favor of answering, and do not begrudge Glaucon and the others a chance to learn.”When I had said this, Glaucon and the others urged him to speak. Thrasymachus plainly wanted to speak and win admiration, convinced he had a splendid answer; but he pretended to insist that I must be the one to answer. At last he yielded, 338b and then said, “This is Socrates’ famous wisdom: he refuses to teach anything himself, but goes about learning from others without even paying them thanks.”“It is true that I learn from others, Thrasymachus,” I said, “but when you say I pay them no thanks, that is false. I pay as much as I can: I can offer praise, though I have no money. You will know at once how readily I offer it when someone seems to speak well, as soon as you answer. For I expect you to speak well.” 338c“Then listen,” he said. “I say that the just is nothing other than the advantage of the stronger. Why do you not praise me? You will not, of course.”“Not until I learn what you mean,” I said. “As yet I do not know. You say the advantage of the stronger is just. But what do you mean by this, Thrasymachus? Surely you do not mean, for instance, that if the wrestler Polydamas is stronger than we are and beef is advantageous for his body, that food is 338d advantageous and just for us too, who are weaker than he is.”“You are repulsive, Socrates,” he said, “and you seize on the interpretation that will do the greatest damage to the argument.”“Not at all, my good man,” I said. “Only make your meaning clearer.”“Do you not know,” he said, “that some cities are ruled by tyrants, some by democracies, and others by aristocracies?”“Of course.”“And in each city, the ruling power is the stronger?”“Certainly.” 338e“Each ruling power makes laws for its own advantage: a democracy makes democratic laws, a tyranny tyrannical laws, and the rest do likewise. Once they have made them, they declare that what is advantageous to themselves is just for their subjects, and punish anyone who departs from it as a lawbreaker and a wrongdoer. This, my good man, is what I mean when I say that in all cities justice is the same thing:

339a the advantage of the established government. That government has the power, so anyone who reasons correctly must conclude that justice everywhere is the same: the advantage of the stronger.”“Now I understand what you mean,” I said, “but I will try to find out whether it is true. So you too, Thrasymachus, have answered that justice is something advantageous—though you forbade me to give that answer—with the addition of ‘to the stronger.’” 339b“A small addition, perhaps,” he said.“It is not yet clear whether it is small. What is clear is that we must examine whether what you say is true. For I agree that justice is something advantageous, but you add that it is advantageous to the stronger, and that is something I do not know. We must examine it.”“Examine it,” he said.“I shall,” I said. “Tell me: do you not also say it is just to obey the rulers?”“I do.” 339c“Are the rulers in every city incapable of error, or can they make mistakes?”“Surely they can make mistakes,” he said.“Then when they undertake to make laws, they make some correctly and some incorrectly?”“I suppose so.”“By making them correctly, do you mean making laws advantageous to themselves, and by making them incorrectly, ones that are disadvantageous? Or what do you mean?”“That is what I mean.”“And whatever laws they make, their subjects must obey; that is what is just?”“Of course.” 339d“Then, by your account, it is just not only to do what is advantageous to the stronger, but also its opposite: what is disadvantageous.”“What do you mean?” he asked.“I think I mean what you mean, but let us look more closely. Have we not agreed that rulers, in commanding their subjects to do certain things, sometimes mistake what is best for themselves, and that it is just for their subjects to do whatever their rulers command? Have we not agreed to that?”“I think we have,” he said. 339e“Then consider,” I said, “that you have also agreed it is just to do what is disadvantageous to rulers, the stronger party, whenever they unintentionally command things harmful to themselves and you say it is just for their subjects to do what they command. Does it not then follow of necessity, most wise Thrasymachus, that it is just to do the opposite of what you say? For the weaker are surely commanded to do what is disadvantageous to the stronger.”

340a “Yes, by Zeus, Socrates,” Polemarchus said, “that is perfectly clear.”“If you testify for him,” Clitophon interjected.“And why,” said Polemarchus, “does he need a witness? Thrasymachus himself agrees that rulers sometimes command things harmful to themselves, and that it is just for their subjects to obey.”“What Thrasymachus laid down as just, Polemarchus,” said Clitophon, “was doing what rulers command.”“And what he laid down as just, Clitophon,” said Polemarchus, “was the advantage of the stronger. 340b After laying down both, he agreed that the stronger sometimes command their weaker subjects to do what is disadvantageous to themselves. From these admissions, the advantage of the stronger would be no more just than its disadvantage.”“But,” said Clitophon, “by the advantage of the stronger he meant what the stronger believed to be advantageous to himself. That is what the weaker must do, and that is what he called just.”“That is not how it was said,” replied Polemarchus. 340c“No matter, Polemarchus,” I said. “If that is what Thrasymachus now means, let us accept it that way. Tell me, Thrasymachus: was this what you meant by justice—the thing the stronger believes advantageous to himself, whether it really is or not? Shall we say that is your meaning?”“Certainly not,” he said. “Do you suppose I call a man stronger when he makes a mistake, at the moment he is making it?”“I did think you meant that,” I said, “when you conceded that rulers are not incapable of error but can make mistakes.” 340d“You are a cheat in argument, Socrates,” he said. “For instance, do you call a man a doctor, precisely insofar as he makes a mistake about a patient? Or a man skilled in calculation, when he makes a mistake in calculation, at the moment of his mistake and in virtue of that mistake? I suppose we use expressions such as ‘the doctor made a mistake,’ or ‘the calculator made a mistake,’ or ‘the teacher made a mistake.’ But in my view, each of these, insofar as he is 340e what we call him, never makes a mistake. So, to speak precisely, since you insist on precision, no practitioner of an art makes a mistake. The man who errs does so when his knowledge fails him, and at that point he is no practitioner. No practitioner, wise man, or ruler makes a mistake insofar as he is a ruler, though everyone will say that the doctor made a mistake or the ruler made a mistake.“That, then, is how you should take the answer I gave you just now. To speak with utmost precision, a ruler, insofar

341a as he is a ruler, does not make mistakes; being free of error, he makes laws for what is best for himself, and his subject must obey them. So, as I said from the start, I call it just to do what is advantageous to the stronger.”“Very well, Thrasymachus,” I said. “Do I seem to you to cheat?”“Absolutely,” he said.“You think I asked what I asked as part of a plot to trip you up in the argument?”“I am sure of it,” he said. “And it will do you no good: 341b you will not trick me without my noticing, nor, once I notice, will you be able to overpower me in argument.”“I would not even try, blessed man,” I said. “But to prevent this from happening again, define for us whether you mean ‘ruler’ and ‘stronger’ in the common way of speaking, or in the precise sense you just described, whose advantage it will be just for the weaker to promote.”“I mean ruler in the most precise sense,” he said. “Now use your tricks and cheat if you can; I give you no quarter. But you will not be able to.” 341c“Do you think,” I asked, “I am mad enough to try to shave a lion and trick Thrasymachus?”“You just tried,” he said, “though you are no match for it.”“Enough of that,” I said. “Tell me: the doctor in the precise sense you spoke of just now—is he a moneymaker or a healer of the sick? Speak of someone who really is a doctor.”“A healer of the sick,” he said.“And a captain? Is a captain in the true sense a ruler of sailors or a sailor?”“A ruler of sailors.” 341d“We should not count the fact that he sails aboard the ship, I imagine, nor should we call him a sailor. He is called captain not because he sails, but because of his art and his command over the sailors.”“True,” he said.“Then is there something advantageous to each of these people?”“Certainly.”“And is not each art,” I asked, “by its very nature devoted to seeking out and providing what is advantageous to its object?”“It is,” he said.“Is there any advantage to each art itself beyond being as complete as possible?” 341e“What do you mean by that question?”“Suppose you asked me,” I said, “whether a body is sufficient simply by being a body, or whether it needs something further. I would say it certainly needs something further. That is why the art of medicine has now been discovered: the body is deficient, and its condition alone is not enough. The art was established to provide what benefits it. Would you say I was right to put it this way, or not?”“Yes,” he said.

335a but someone who only seems good, without being good, only seems to be a friend and isn't one. The same rule applies to an enemy.”

“On that account,” I said, “a good person will be a friend, it seems, and a bad person an enemy.”

“Yes.”

“Then you want us to add something to our first account of justice. We said it was just to do good to a friend and harm to an enemy. Now you want us to say it's just to do good to a friend who is good and to harm an enemy who is bad?” 335b

“Yes,” he said. “That sounds right to me.”

“Then is it right for a just man to harm any other human being?” I asked.

“It certainly is,” he said. “He should harm bad people who are his enemies.”

“When horses are harmed, do they become better or worse?”

“Worse.”

“Worse at the qualities that make dogs good, or those that make horses good?”

“At the qualities of horses.”

“And when dogs are harmed, they become worse at being good dogs, not good horses?”

“They must.” 335c

“Then shouldn't we say the same of human beings, my friend? When they're harmed, don't they become worse at the qualities that make human beings good?”

“Yes.”

“And isn't justice a human virtue?”

“That follows too.”

“So when human beings are harmed, my friend, they must become more unjust.”

“It seems so.”

“Can musicians use music to make people unmusical?”

“No.”

“Can people skilled with horses use horsemanship to make others bad at it?”

“No.”

“Then can just people use justice to make others unjust? Or, 335d to put it generally, can good people use virtue to make others bad?”

“That's impossible.”

“It's not the work of heat to make things cold, I think, but of its opposite.”

“Yes.”

“And not the work of dryness to make things wet, but of its opposite.”

“Exactly.”

“And it's not the work of a good person to harm others, but of his opposite.”

“So it seems.”

“And a just person is good?”

“Certainly.”

“So it's not the work of a just person to harm a friend or anyone else, Polemarchus. That's the work of his opposite, an unjust person.”

“I think you're completely right, Socrates,” he said. 335e

“Then if someone says justice is giving each person what is owed and means that a just man owes harm to his enemies and help to his friends, the person who said this wasn't wise. He was wrong. We've found that it's never just to harm anyone.”

“I agree,” he said.

“Then you and I will join forces against anyone who claims that Simonides said this, or Bias, or Pittacus, or any other wise and blessed man.”

“For my part,” he said, “I'm ready to join the fight.”

336a “But do you know whose saying I think it is,” I asked, “that it's just to help friends and harm enemies?”

“Whose?” he asked.

“I think it's the saying of Periander, or Perdiccas, or Xerxes, or Ismenias of Thebes, or some other rich man who thought he had great power.”

“That's absolutely right,” he said.

“Well then,” I said, “since justice and what is just haven't turned out to be this either, what else could we say justice is?” 336b

While we talked, Thrasymachus had often started to interrupt and take over the discussion. The people sitting beside him kept stopping him because they wanted to hear it through. But when we paused and I asked that last question, he could no longer keep still. He gathered himself like a wild animal and lunged at us as if he meant to tear us apart.

Polemarchus and I were so frightened that we panicked. Thrasymachus shouted out in the middle of the group, “Socrates, what is all this 336c nonsense you've been carrying on with? Why are you two playing the fool, giving way to one another? If you really want to know what justice is, don't just ask questions and then show off by refuting each answer. You know it's easier to ask than to answer. Give an answer yourself. Tell us what you say justice is. And don't tell me it's 336d what is right, or useful, or profitable, or gainful, or advantageous. Say clearly and precisely what you mean. I won't accept empty talk like that.”

His words stunned me. I looked at him in fear. I think I would have been struck speechless if I hadn't seen him before he saw me. But I had looked at him first, just as our discussion was beginning to make him angry. 336e That let me answer him. I said, with a slight tremble, “Thrasymachus, don't be angry with us. If he and I have made mistakes as we examine these arguments, you can be sure we haven't done so on purpose. If we were looking for gold, do you think we'd deliberately give way to each other and ruin our chances of finding it? We're looking for justice, something worth far more than a lot of gold. Do you think we'd be so foolish as to keep yielding to each other instead of doing our best to find it? You may think so, my friend, but I believe we simply aren't able to find it. So you skilled men should have much

337a more pity for us than anger.”

When he heard this, he gave a harsh laugh. “By Heracles! Here's Socrates' usual act of pretending not to know. I knew it, and I told everyone here: you wouldn't be willing to answer. You'd pretend not to know and do anything rather than answer a question.”

“That's because you're clever, Thrasymachus,” I said. “You know that if you asked someone what twelve is and warned him in advance, 337b ‘Don't tell me twelve is twice six, or three times four, or six times two, or four times three. I won't accept that sort of nonsense,’ then no one could answer a question asked that way. But suppose he said to you, ‘Thrasymachus, what do you mean? I mustn't give any of the answers you listed? Not even if one of them is right? Am I to say something 337c other than the truth? What do you mean?’ What would you say to him?”

“Well,” he said, “as if that case were like this one!”

“There's nothing to prevent it from being like this one,” I said. “But even if it isn't, if it seems similar to the person being questioned, do you think he will be any less likely to give the answer he thinks right, whether we forbid it or not?”

“So that's exactly what you'll do, is it?” he asked. “You'll give one of the answers I ruled out?”

“I wouldn't be surprised,” I said, “if, after thinking it over, that was what seemed right to me.” 337d

“Suppose I give a different answer about justice,” he said, “one better than all those. What do you think you deserve then?”

“What else but what a person who doesn't know deserves?” I said. “He should learn from someone who does. That's what I think I deserve.”

“Very funny,” he said. “But besides learning, you must pay money too.”

“I will as soon as I have some,” I said.

“He does have some,” Glaucon said. “Go ahead and speak, Thrasymachus, if it's money you want. We'll all contribute for Socrates.” 337e

“I'm sure you will,” Thrasymachus said, “so that Socrates can do what he always does: refuse to answer, then seize on somebody else's answer and refute it.”

“But my good man,” I said, “how could a person answer when he doesn't know, says he doesn't know, and, even if he has an opinion, has been told by a capable man that he may not say anything he thinks? It's much more reasonable for you

338a to speak. You say you know and have an answer to give. Please do answer me. Do me that favor, and don't begrudge Glaucon and the others the chance to learn too.”

When I said this, Glaucon and the others asked Thrasymachus to speak. He clearly wanted to, hoping to impress everyone; he thought he had a splendid answer. But he pretended to insist that I should answer. In the end he agreed. 338b “This,” he said, “is Socrates' famous wisdom: he refuses to teach anything himself, but goes around learning from others without even thanking them.”

“You're right that I learn from others, Thrasymachus,” I said. “But you're wrong that I don't thank them. I give what I can, which is praise; I have no money. You'll soon see how eagerly I praise someone when I think he speaks well. I expect you to give a good answer.” 338c

“Listen, then,” he said. “I say justice is nothing other than the advantage of the stronger. Well, why aren't you praising me? Of course you don't want to.”

“First let me understand what you mean,” I said. “I don't yet. You say justice is the advantage of the stronger. What do you mean by that, Thrasymachus? Surely you don't mean this: if the wrestler Polydamas is stronger than we are, and beef helps build his body, then that food is both advantageous and just 338d for us, who are weaker than he is.”

“That's a disgusting way to argue, Socrates,” he said. “You choose the interpretation most likely to spoil what I'm saying.”

“Not at all, my good man,” I said. “Just tell me more clearly what you mean.”

“Don't you know,” he said, “that some cities are ruled by tyrants, others by democracies, and others by aristocracies?”

“Of course.”

“And in each city the ruling group has the power?”

“Yes.” 338e

“Each ruling group makes laws to its own advantage: a democracy makes democratic laws, a tyranny makes tyrannical laws, and the others do the same. Once they've made the laws, they declare that obeying what's to their advantage is just for their subjects. They punish anyone who steps outside those laws as a lawbreaker and wrongdoer. So here's what I mean, my good man. In every

339a city justice is the same thing: the advantage of the established government. Since that government has power, anyone who reasons correctly can see that justice is the same everywhere: the advantage of the stronger.”

“Now I understand what you mean,” I said. “I'll try to find out whether it's true. You too answered that justice is something advantageous, Thrasymachus, though you forbade me to give that answer. You added ‘of the stronger.’” 339b

“A tiny addition, perhaps,” he said.

“It's not yet clear whether it's tiny. But we clearly need to examine whether your claim is true. I agree that justice is something advantageous; you add that it's the advantage of the stronger. I don't know if that's right, so we need to examine it.”

“Go ahead,” he said.

“I will. Tell me, don't you also say it's just to obey those in power?”

“I do.” 339c

“Are the rulers in each city incapable of making mistakes, or can they make some?”

“They can certainly make mistakes,” he said.

“Then when they try to make laws, they make some correctly and some incorrectly?”

“I think so.”

“By ‘correctly,’ do you mean they make laws advantageous to themselves, and by ‘incorrectly,’ laws that aren't advantageous? Or what do you mean?”

“That's what I mean.”

“And their subjects must do whatever they prescribe, and doing that is just?”

“Of course.” 339d

“So according to your account, it's just not only to do what's advantageous to the stronger, but also to do the opposite, what's not advantageous.”

“What are you talking about?” he asked.

“I think I'm talking about what you are. Let's look more carefully. Haven't we agreed that rulers sometimes make mistakes about what's best for themselves when they give orders to their subjects? And haven't we agreed that it's just for subjects to do whatever the rulers order? Haven't we agreed on that?”

“I think so,” he said. 339e

“Then realize that you've also agreed it's just to do things that are disadvantageous to the rulers, the stronger people. When rulers mistakenly order things that are bad for themselves, you say it's just for their subjects to do what they ordered. So, wise Thrasymachus, doesn't it follow necessarily that justice can be the opposite of what you said? The weaker people are ordered to do what is disadvantageous to the stronger.”

340a “Yes, by Zeus, Socrates,” Polemarchus said. “That's perfectly clear.”

“If you're going to testify for him,” Clitophon broke in.

“Why does he need a witness?” Polemarchus asked. “Thrasymachus himself agrees that rulers sometimes order things that are bad for themselves, and that it's just for their subjects to obey.”

“Thrasymachus said it was just to obey the rulers' orders, Polemarchus.”

“And he said that justice was what benefits the stronger, Clitophon. 340b He made both claims and then agreed that the stronger sometimes tell the weaker people, their subjects, to do what is disadvantageous to themselves. Given these admissions, doing what benefits the stronger would be no more just than doing what doesn't benefit them.”

“But,” Clitophon said, “by what benefits the stronger he meant what the stronger believes benefits him. The weaker person must do that, and that's what he called just.”

“That isn't what he said,” Polemarchus replied. 340c

“It doesn't matter, Polemarchus,” I said. “If that's what Thrasymachus means now, let's accept it as his account. Tell me, Thrasymachus, is that what you meant by justice: what seems advantageous to the stronger, whether it actually is or not? Should we say that's your position?”

“Certainly not,” he said. “Do you think I call someone ‘the stronger’ at the very moment he makes a mistake?”

“I thought you did,” I said, “when you agreed that rulers aren't incapable of error but can make mistakes.” 340d

“You're twisting my words, Socrates,” he said. “Do you call a man a doctor, strictly speaking, when he makes a mistake in treating patients, at the moment and in the respect that he makes it? Or do you call someone an expert at calculation when he makes a mistake in calculating, at that very moment and in respect of that mistake? We do say, loosely, ‘The doctor made a mistake,’ or ‘The calculator made a mistake,’ or ‘The teacher made a mistake.’ But in my view, insofar as each is what we call him, 340e he never makes a mistake. To speak precisely, since you care so much about precision, no skilled practitioner makes a mistake. A man goes wrong when his knowledge fails him; at that point he isn't exercising his skill. So no skilled practitioner, wise man, or ruler makes a mistake while acting as such, though everyone would say that a doctor made a mistake or a ruler made a mistake.

“Take my earlier answer that way. More precisely, a ruler, insofar as he is a ruler, 341a doesn't make mistakes. Since he doesn't make mistakes, he sets down what's best for himself, and his subject must do it. So, as I said at the start, justice is doing what benefits the stronger.”

“All right, Thrasymachus,” I said. “Do you think I'm twisting your words?”

“I certainly do,” he said.

“You think I deliberately asked those questions to cause trouble for your argument?”

“I know you did,” he said. “But it won't help you. You won't trick me without my noticing; and if I notice, you won't be able to overpower me in argument.” 341b

“I wouldn't even try, my friend,” I said. “But so that this doesn't happen again, tell me which sense of ‘ruler’ and ‘stronger’ you mean. Do you mean a ruler in ordinary speech, or a ruler in the precise sense you just described, whose advantage it will be just for the weaker person to pursue?”

“I mean a ruler in the strictest sense,” he said. “Now make trouble and twist my words if you can. I won't give you any leeway. But you won't manage it.” 341c

“Do you think I'm crazy enough to try to shave a lion,” I asked, “or to twist Thrasymachus's words?”

“You just tried,” he said, “and you weren't up to it.”

“Enough of that,” I said. “Tell me this: the doctor in the precise sense you mentioned just now, is he a moneymaker or someone who cares for the sick? I mean a doctor who really is a doctor.”

“Someone who cares for the sick,” he said.

“What about a ship's captain? Is a real captain a sailor or the person in charge of the sailors?”

“The person in charge of the sailors.” 341d

“We shouldn't count the fact that he sails on the ship, I think, and call him a sailor. He's called a captain not because he sails but because of his skill and his authority over the sailors.”

“True,” he said.

“Doesn't each group he cares for have something that benefits it?”

“Certainly.”

“And isn't each skill meant to discover and provide that benefit for its group?” I asked.

“Yes,” he said.

“Then does each skill have any benefit of its own apart from being as complete as possible?” 341e

“What do you mean by that question?”

“Suppose you asked me whether a body can get by merely by being a body, or whether it needs something else,” I said. “I'd answer that it certainly needs something else. That's why the art of medicine has been developed: a body has shortcomings and can't get by in that condition. Medicine was organized to provide what's beneficial to it. Do you think I've put that correctly, or not?”

“Correctly,” he said.