"Behold! human beings living in an underground den"
About half way through "The republic" takes a dramatic turn. Up until this point Socrates had been talking about ideas in broad sweeps, doing little to tie things together. Book 7 focuses on the individual. The seeker of true knowledge and the tribulations he must go through to find it. Socrates also, through his words, shows his poetical skills. One would think that Socrates, after all his criticisms of poetry would not fall back to lyrical devices to explain his meaning but he does. Book 7 of "The republic" is in my (very humble) opinion the greatest allegory in literature. So draw the curtains. Dim the lights. Turn the music off. We are going into the cave.
Socrates wants you to imagine an underground den with a single opening towards the light. Across the den there are rows of humans chained so that they can't move in any direction. They can only see what's in front of them. And in front of them is a screen also running along the cave. On this screen they see shadows projected by the fire blazing the distance.
"The truth would be literally nothing but the shadows of the images"
They see men talking with each other, statues, figures of animals... everyday things. They see their own shadows and shadows of objects which the fire throws on the screen. And when they talk to each other they name things that are before them --giving names to shadows. And when they hear the echo in the distance they assume that the sound came from one the passing shadows.
"Will he not fancy that the shadows which he formerly saw are truer than the objects which are now shown to him?"*
Now Socrates wants you to picture the state of a prisoner who is freed from his captivity. As he stands on his feet for the first time and starts to look around he will experience confusion in the mind and pain in the body. As he moves towards the light he will turn his eyes away due to the glare. He will seek refuge among the objects that he already understands-- the ones that his vision sees. Now if this prisoner is dragged by force to ascent to the light he will be dazzled, completely overwhelmed and will be unable to comprehend the realities.
He will need to become accustomed to the light little by little. First he will see only the shadows, then the reflections in water, then the night sky and the stars and finally when he is ready he will see the sun. The single source of truth.
Then Socrates goes on to enumerate the responsibility of the person who has seen the light. The natural state of the person who has seen the light, he says, is of glee. Once the person has ascended he does not want to look down. And yet in a Socratic society it is duty of the person to go back. He has to suffer once more, this time by descending from a state of knowledge and light to the depths of ignorance and darkness. Once more he will need to become accustomed to the darkness but once he does he will be able to see 10000 times better and will be in a position to help his fellow prisoners.
The cave of Socrates is used in many forms in literature and other methods of entertainment. Count of Monte cristo is a classic example of a man seeking enlightenment. Count passes his initial years in captivity struggling to accept the judgment of fate. He resigns from life and there is hardly any spunk left in him. Until he meets an old man who becomes his instructor. The balm of knowledge infuses in him a fresh courage and frees him of spiritual chains that many years of imprisonment had locked him in. What he does after gaining knowledge is completely against Socratic principles but that is besides the point.
Another story which uses the allegory of the cave is "The Bet" by Anton Chekhov in which a young lawyer goes under a willful imprisonment. At first to win a stupid bet. As the years pass by he fights isolation , his own weakening will and the continuous stream of knowledge that is too much for him to digest.
The cave also presents in new light the refrain of Dr. House "Everybody lies". Everybody lies not because they want to but because they don't know the truth. They see the shadows and take them as real. Never stopping to question. Often his team takes the patient's word on it's merit which causes them to go in a completely wrong direction until Dr. House who is more critical in his methods decides to question the statements. Of causes the show plays around with the literal and symbolic meaning of the phrase in different situations.
If you look carefully nearly every story of struggle is an instance of the prisoner seeking the blinding light. The light is not the Sun in all cases but a stronger flame. Even so standing up to the light when one has lived all one's life in darkness requires the same mental and bodily conditioning as described.
If you have the time and the inclination you should read "The republic" in it's entirety but if you were to read only one chapter Book 7 would be it. At best it is a 45 min read on a lazy afternoon or on a rainy evening. But the words carry such weight that it is sure to change in some little way the way you perceive things.
What I'm trying to say is that this is a book that will change you. Not physically because if you look in the mirror and examine your left cheek and then your right cheek they will appear to be exactly the same as you left and right cheeks before reading the book. Unless, you know, it has been years since you read. But internally you will have changed.