The last volume is about educating the guardians and reviewing the stories told to them since childhood, thus expressing some views on God. Enter the third volume and continue the topic of education of city-state guardians and citizens. Socrates believes that guardians should not be afraid of death, so they should delete the poet's bad description of hell and praise life in hell. Socrates also mentioned that children and adults should be free, should be afraid of becoming slaves, and should not be afraid of death. Regarding freedom, as far as education is concerned, I think that if a person wants to be free, the education we receive should be all-round, not one-sided. Because we are human beings, we must learn the knowledge that belongs to all mankind, and human beings have many aspects, including good and evil, beauty and ugliness, body and art. If you can only receive some knowledge, it will be shaped as one-sided, and the result may be serious. For example, terrorist organizations only pay attention to the evil side in the education of their members, thus creating terrorists in our eyes. For those who only receive a good education in Plato's Republic, they may think that this is against heaven, and the values of both sides are contradictory. What is right? There should be no problem with each other's academic qualifications. At this time, I think the problem lies in education. The education received by both sides is one-sided. If we develop ourselves by this means, our thoughts will be solidified very one-sided. We can't make a fair judgment, we can't think comprehensively, we can't think comprehensively, that is, we don't have enough freedom, because we all make judgments on the basis of what we have. We think that we are making free choices, but in fact we are subject to our own cognitive background. Then, if we look at whether a person is free from a comprehensive understanding of world life, does human beings have absolute freedom? I don't think so, because absolute freedom requires an absolutely comprehensive understanding of world life, and we are influenced by our own educational background, life experience and IQ level. And it is impossible to have an absolutely comprehensive understanding, so absolute freedom and thus absolute justice are impossible, so we can settle for the second best and pursue the greatest freedom and justice, which requires us to obtain the widest scope. The most comprehensive education, so as far as Plato's Republic is concerned, the people living in it are confined to their most basic education, so the people inside cannot be free or fair, which means that the city-state entity is unfair to its citizens. As Socrates said, it is ironic to discuss justice on the larger level of polis, and it is impossible to have a result. Then he talked about deleting some terrible terms, such as crying, lamentation, uncontrolled laughter of heroes, and talking about not lying except rulers, doctors and a few people who can lie in order to safeguard national interests and treat patients. He also described self-restraint, holding that the most important thing for ordinary people's self-restraint is to obey their rulers, while the most important thing for rulers' self-restraint is to control their desire for physical happiness, such as diet. Therefore, all the unrestrained descriptions in poetry should be deleted, and once again, God is only the source of good, not evil. All the above have stipulated the description of gods, gods, heroes and the underworld in the poem. Next, I began to discuss the terms about people's opinions. According to my own understanding of justice, Socrates believes that people who are contrary to his understanding should not be allowed to publicize their views everywhere, but should say what Socrates thinks. Aderman toth agreed with Socrates. There is a problem here. Aderman Toth has no objection to Socrates' view of justice. He seems to have completely forgotten Glaucon's opposite view of justice in the second volume. Look at volumes three and two. Aderman Toth had almost no objection to Socrates' view that there was no theoretical basis and no reason, but kept answering yes, extremely, of course, without any objection at all. It seems that this person is redundant. I think this may also be a bad place for Plato's style. For the progress of the content, it wastes space, takes up time and even loses interest by stiffly shaping several characters. Then Socrates said that the discussion on the content of the story was over, and then the discussion on the form and style of the story began. Socrates told Aderman Toth that there are two ways for poets to tell stories: narration and imitation. Narration means that the author tells the story in his own tone, while imitation means that the author tells the story in the tone of the characters in the story. Then Socrates divides the style of poetry into three forms, the first is the tragedy and drama that only uses imitation, the second is the lyric poem that only uses narrative hymns, and the third is the poetic style of epic that uses both narrative and imitation. Then, from the imitation in the poem, I talked about the imitation of people. Socrates believes that people should do what they are good at, that is, one should only do what one should do, and should not imitate to do other things. For guardians, if they want to imitate, they can only imitate those who have proper relationship professionally, that is, those who are brave, temperate, pious and free. On the contrary, they cannot imitate them. As for the forms of poems and tunes, Socrates thinks that there is no difference between the words sung and the words spoken, so he should abandon the elegy tunes such as Lydia tunes mixed with high notes and the soft and decadent Ionia tunes, and only ask doria to reconcile the Francia tunes. In terms of musical instruments, only the lyre used by Apollo, which represents rationality, is used. For rhythm, only the brave rhythm representing order is used. The good words, good monotony, good style and good rhythm mentioned above all come from the really good mental state of those people with good intelligence and good personality. To achieve such a good mental state, young people ask artists to let their works of art only describe the works with good mental state mentioned above, but not the works with bad mental state. After children receive these good education in childhood, they will be polite, love beauty and oppose ugliness when they grow up. This is also the reason why children should attach importance to literature and art education from an early age. Socrates believes that the most beautiful person should be the inner beauty of spirit and the outer beauty of posture and behavior. And think that the inner spiritual beauty is more important than the outer physical beauty. After discussing music education, we began to discuss sports. We believe that the external body should be dominated and restrained by the internal spirit, and a good attitude and personality can make the natural physique reach the best. Guardians should not drink too much, sleep too much, exercise in various ways, eat sweets or eat complicated food, and keep healthy with simple physical exercise. They should control themselves, not indulge. If they have no self-control, they should not indulge. People's health is very important, and it is the basis for making contributions to the country. People can get sick, but they can't delay their work. Socrates believes that if they delay their work in order to cure diseases, they should not. For those rich people who don't have to work and those who are born sick and useless to others, they don't deserve to be treated. Even such people should not be allowed to give birth to offspring with the same poor physique. Might as well be dead. Next, what is the best worker? A good worker must first have a good spirit, then be experienced and have a good old age, because people with bad hearts can only know bad people, but not good people. Because their hearts are bad and there is no prototype of kindness, they are smart to deal with bad people, but good people can't help it. Good people can finally understand evil and virtue through education, so only good people can become good workers. I think the answer given by Socrates is problematic, because since good people can understand bad people, why can't bad people understand good people? Since good people have natural virtue, and natural virtue can finally understand evil and virtue itself through education, why can't bad people have natural evil? And why can't we understand good and evil itself through education? If good can understand evil, then evil can certainly understand good. I think Socrates' argument in 409B is untenable. Then Socrates demonstrated that people should combine music and physical education and training with each other, not favoring one over the other, and combining gentleness and courage to be harmonious with each other. Then we talked about how to decide who is the ruler and who is the ruled among citizens. Socrates thinks that the ruler should be an old man who is wise and capable of protecting the country, caring about the national interests and never willing to do anything detrimental to the national interests. From childhood to adulthood, we should inspect them at any time, let them work hard and work hard, be wary of the enemy externally, and pay attention to friends internally, so that friends will not be reconciled, and the enemy will not dare to harm the polis, while the rest. Moreover, it is necessary to instill such an idea in the people in the polis that the fate and nature of human beings have long been decided by heaven, but they are mixed in the world and cannot be distinguished. Go up if you can, and go down if you can't. Because it helps people to love their country, stabilize the city-state and benefit the rule. Socrates also mentioned here that it is difficult to convince the rulers of this idea. Perhaps that is to say, this idea is just a means of ruling and a way to safeguard national interests. For rulers, they represent the smartest people, and they won't believe this statement. Socrates may mean that the state, religion, or group, the upper class people are hiding the truth from the lower class people, and for the sake of the stability of the rule and the interests of the class, they do not hesitate to fool the people, let them live in fantasy, be content with their own standards without making progress, and become prisoners in the lies of the rulers. Finally, Socrates believes that in order to protect the polis and resist the enemy and realize absolute loyalty to the polis, you can't own any property, and the necessities of life can only be supplied by the people. In a word, the third volume followed by the second volume discusses the music and physical education for guardians and citizens, and talks about the conditions for guardians to become rulers, as well as some political thoughts.