Setting the Scene
Picture men dwelling in a sort of subterranean cavern with a long entrance open to the light on its entire width. Conceive them as having their legs and necks fettered from childhood, so that they remain in the same spot, able to look forward only, and prevented by the fetters from turning their heads. Picture further the light from a fire burning higher up and at a distance behind them, and between the fire and the prisoners and above them a road along which a low wall has been built, as the exhibitors of puppet shows have partitions before the men themselves, above which they show the puppets.
See men carrying past the wall implements of all kinds that rise above the wall, and human images and shapes of animals as well, wrought in stone and wood and every material, some of these bearers presumably speaking and others silent.
Do you think that these men would have seen anything of themselves or of one another except the shadows cast from the fire on the wall of the cave that fronted them?
How could they, he said, if they were compelled to hold their heads unmoved through life?
And again, would not the same be true of the objects carried past them?
If then they were able to talk to one another, do you not think that they would suppose that in naming the things that they saw they were naming the passing objects?
And if their prison had an echo from the wall opposite them, when one of the passers-by uttered a sound, do you think that they would suppose anything else than the passing shadow to be the speaker?
By Zeus, I do not, said he.
Then in every way such prisoners would deem reality to be nothing else than the shadows of the artificial objects.