The cave

SOCRATES: Imagine this: People live under the earth in a cavelike dwelling. Stretching a long way up toward the daylight is its entrance, toward which the entire cave is gathered. The people have been in this dwelling since childhood, shackled by the legs and neck..Thus they stay in the same place so that there is only one thing for them to look that: whatever they encounter in front of their faces. But because they are shackled, they are unable to turn their heads around. A fire is behind them, and there is a wall between the fire and the prisoners SOCRATES: Some light, of course, is allowed them, namely from a fire that casts its glow toward them from behind them, being above and at some distance. Between the fire and those who are shackled [i.e., behind their backs] there runs a walkway at a certain height. Imagine that a low wall has been built the length of the walkway, like the low curtain that puppeteers put up, over which they show their puppets. The images carried before the fire SOCRATES: So now imagine that all along this low wall people are carrying all sorts of things that reach up higher than the wall: statues and other carvings made of stone or wood and many other artifacts that people have made. As you would expect, some are talking to each other [as they walk along] and some are silent. GLAUCON: This is an unusual picture that you are presenting here, and these are unusual prisoners. SOCRATES: They are very much like us humans, I [Socrates] responded. What the prisoners see and hear SOCRATES: What do you think? From the beginning people like this have never managed, whether on their own or with the help by others, to see anything besides the shadows that are [continually] projected on the wall opposite them by the glow of the fire. GLAUCON: How could it be otherwise, since they are forced to keep their heads immobile for their entire lives? SOCRATES: And what do they see of the things that are being carried along [behind them]? Do they not see simply these [namely the shadows]? GLAUCON: Certainly. SOCRATES: Now if they were able to say something about what they saw and to talk it over, do you not think that they would regard that which they saw on the wall as beings? GLAUCON: They would have to. SOCRATES: And now what if this prison also had an echo reverberating off the wall in front of them [the one that they always and only look at]? Whenever one of the people walking behind those in chains (and carrying the things) would make a sound, do you think the prisoners would imagine that the speaker were anyone other than the shadow passing in front of them? GLAUCON: Nothing else, by Zeus! SOCRATES: All in all, I responded, those who were chained would consider nothing besides the shadows of the artifacts as the unhidden. GLAUCON: That would absolutely have to be.