Plato’s Republic book seven describes the cave metaphor. It tells a group of prisoners in a cave; they had being held there for a long period of time. Their necks and legs were chained against the wall. That’s why they can only look forward. There is a low wall blocking the hole, they can see the shadows of men and animals also they can hear the voices. This will make them think what the real world looks like. At a point if a prisoner who breaks the chains and leave the cave, he will discover how the real world is like, and will criticize the past life inside the cave.
Regarding to whether or not this freed prisoner should go back to cave and tell everyone the truth. Glaucon said that’s a philosopher’s responsibility. The philosopher’s responsibility in real life is to pleasure the entire state conditions and how the make better rules. Socrates says who masters dialectics have the ability to use the most scientific method to answer questions. Young people, whom receive higher honors in the first step, will have to do good continuously because defeating will make them lose faith in justice. So the author believes that philosophers have to educate those Youngers, tirelessly until the next successor to be trained.