as mention above, it's plato myth of the cave. this is the second last thing we learn last week. in it there were six object that symbolizes thing:

1. the prisoner 
2. the chain 
3. the fire 
4. the shadow and the images 
5. the puppet player 
6. the old man 

The prisoners are described as being bound in a dark cave, facing into a wall. They can only see the shadows of their guards as they come and go behind them. It is as if the shadows are the reality, real people who can talk and move.

Plato also uses the light (the Sun outside, brighter than the cave lights) as a metaphor for intellectual illumination, which could only with difficulty be explained to those who had not experienced it firsthand.

The old man in this is the one who set free of the prisoner from a mere oblivion set by their dream.  Plato compares this very limited view of the world with the ordinary physical perceptions of mankind. Plato believes that true reality is much more than what we perceive, and that a philosopher's role is to investigate this higher meaning for the enlightenment of all. To that end, he postulated that all earthly things were simply representations (like the shadows) of some higher form or concept, much as all wooden tables in the world mirror the same basic function that is "a table. 


In conclusion, the interior of the cave is the imprisonment of people by their bodies and by themselves. People must look into the light to gain knowledge, which are what Plato and his mentor Socrates held most important. The sun is their way of gaining this knowledge as it allows people to see the truth as long as the practice reason or thinking along with it. It also makes visible the distinction between what is good and what is false.