They discovered the sun, which Plato uses as an analogy for the fire that man cannot see behind.
Like the fire that cast light on the walls of the cave, the human condition is forever bound to the impressions that are received through the senses.
Behind the prisoners is a fire, and between the fire and the prisoners is a raised walkway with a low wall, behind which people walk carrying objects or puppets "of men and other living things" (514b).
The people walk behind the wall so their bodies do not cast shadows for the prisoners to see, but the objects they carry do ("just as puppet showmen have screens in front of them at which they work their puppets" (514a)).
The chains that prevent the prisoners from leaving the cave represent that they are trapped in ignorance, as the chains are stopping them from learning the truth.
Plato Essay Cave
The shadows cast on the walls of the cave represent the superficial truth, which is the illusion that the prisoners see in the cave.In other words, we would encounter another "realm", a place incomprehensible because, theoretically, it is the source of a higher reality than the one we have always known; it is the realm of pure Form, pure fact. Left (From top to bottom): The Sun; natural things; reflections of natural things; fire; artificial objects; shadows of artificial objects; Allegory level.Right (From top to bottom): "Good" idea, Ideas, Mathematical objects, Light, Creatures and Objects, Image, Analogy of the Sun, and the Analogy of the Divided Line.The freed prisoner represents those who understand that the physical world is only a shadow of the truth, and the sun that is glaring the eyes of the prisoners represents the higher truth of ideas.The light further represents wisdom, as even the paltry light that makes it into the cave allows the prisoners to know shapes.Even if these interpretations (or, in Kantian terminology, intuitions) are an absurd misrepresentation of reality, we cannot somehow break free from the bonds of our human condition—we cannot free ourselves from phenomenal state just as the prisoners could not free themselves from their chains.If, however, we were to miraculously escape our bondage, we would find a world that we could not understand—the sun is incomprehensible for someone who has never seen it.The Allegory of the Cave, or Plato's Cave, was presented by the Greek philosopher Plato in his work Republic (514a–520a) to compare "the effect of education (παιδεία) and the lack of it on our nature".It is written as a dialogue between Plato's brother Glaucon and his mentor Socrates, narrated by the latter.The prisoners, according to Plato, would infer from the returning man's blindness that the journey out of the cave had harmed him and that they should not undertake a similar journey.Plato concludes that the prisoners, if they were able, would therefore reach out and kill anyone who attempted to drag them out of the cave (517a).