(summary) "the allegory of the cave"

In “Excerpt From The Republic”, Socrates tries to explain how far our nature is enlightened or unenlightened by using an example of prisoners who used to live in a cave. In the cave, their movements are restricted by chains which make them only see a low wall in front of them. Behind of them, there is a blazing fire and between the fire and the prisoners, there are men carrying statues and figures made by various materials so that they only see the people’s shadows on the low wall. For the prisoners, shadows of people’s images and sounds are the only real world. They have been believed it for their entire lives.

In this situation, if those prisoners are released and experience outside of the cave, the first thing they face will be very painful and cannot see things clearly because of a sun that they have never been experienced before. If someone approaches to them and tell them what they see now is the real world, they possibly avoid the truth at first time. They also cannot recognize and name objects near them. They have never seen them before. However, as they have been exposed and used to the real world for more time, they now can see things clearer and break off the old habit in the cave. They are willing to accept a new habit from the real world Therefore; they cannot go back to their old situation of the cave. If they go to the cave and try to inform the real world to the rest of the people who have never moved out from the cave will deny them and they will rather kill them, because their eyes are weak enough to see the shadows clearly, again. So, the rest of prisoners will think that the world of outside ruined their eyes.
Socrates said that the idea of good is barely seen only with an effort, but when it is seen, it is the cause of beautiful and right. So, if someone who wants himself or herself to have a rational behavior, they have to have the idea of good.