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 (???????) 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 allegory is presented after the analogy of the sun (508b-509c) and the analogy of the divided line (509d-511e). All three are characterized in relation to dialectic at the end of Books VII and VIII (531d-534e). Plato has Socrates describe a group of people who have lived chained to the wall of a cave all of their lives, facing a blank wall. The people watch shadows projected on the wall from objects passing in front of a fire behind them, and give names to these shadows. The shadows are the prisoners' reality.