Plato's Allegory of The Cave
Shadows On A Cave Wall
We are first asked by Socrates to imagine prisoners within a cave. These prisoners have known only this cave, they have been born into it. Their legs are bound with chains and their heads are fixed forward so that all they can see is the wall of the cave before them. Behind them is lit a large fire and in between the prisoners and the fire is a ramp on which men walk with objects affixed to their heads. These objects are animal and human forms amongst other commonplace things. The shadows of these objects cast upon the walls are the only nebulous impressions that they have access to and are taken as comprising the reality of the world by the prisoners since they have known nothing else. The prisoners hear the sounds of the people walking on the wooden plank behind them and attribute the sounds of these particular treads and gaits to the shadow objects parading before them. Under such conditions the man who is best able to connect the noise to the object and thus anticipate what form will be presented next is regarded as the wisest amongst them in the ways of the world.
Into The Light
Socrates asks us to suppose that a prisoner is released from his bondage. He is now free to see the actual carvings that have cast the shadows he has observed his whole life but he is unable to identify them.
Suppose the freed prisoner were forcibly removed from the cave. Would he not be tentative, unsure, even angry at his expulsion. The sun would blind him upon his emergence and he would be unable to see anything that is real or true.
After a time his eyes would adjust and he would for the first time be allowed to see all of the things that make up reality. The objects and animals around him would be his first experience of the genuine as opposed to mere abstraction of abstractions (shadows of representative carvings). He would eventually be able to look upon the sun and recognize it as the source of all things, even of the shadow's on the wall of the cave in that the sun allows for the reality alluded to by those shadows.
Return to Darkness
The freed prisoner would remember his home and what constituted, "worldly knowledge," in that place as pitiful. He would regard the praise and deference given to the bound man who could best guess what shadow would next be cast upon the wall with vitriole.
Upon returning to the cave, his eyes unaccustomed to the dark, he would perform very poorly at the anticipatory task that passed for wisdom amongst the prisoners. Nonetheless, once among the prisoners who had remained, his ineptness at this task would lead them to believe that his eyes and reason had been corrupted by his forced egress from the cave. Ironically, the prisoner's would look upon him with pity and collude to kill any man who might attempt to force them into that corrupting, blinding place of light beyond the cave entrance.
Now this Allegory is rife with metaphor and many of them are readily apparent. It is assumed that the mean level of human knowledge is quite limited, those bound within the cave seeing only shadows of representations of true things represent this low level of worldly understanding. The forced expulsion of the single freed prisoner and his immediate blind pain in the brightness of the sun denote the few who through arduous work and the acquisition of sometimes unpleasant truths elevate their level of comprehension. His condescension upon returning to the cave, regarding their mere guessing game seems to imply a kind of intellectual elitism or pretentiousness. And the pitying regard he receives from the unenlightened prisoners and their resolve to kill before being forced from the cave seems to imply the blissful state of ignorance or at least a weariness amongst the general masses of being corrupted by the unknown.
In the final analysis it seems you can only appreciate what lies outside the cave by experiencing it for yourself and that the understanding that you acquire once in the light cannot be shared with or understood by those who have only known darkness.