  Cave, arguably the most famous analogy in the history of philosophy, reinforces the message of line. Seated prisoners, chained so that they cannot move their heads, stare at a cave wall on which are projected images. These images are cast from carved figures illuminated by a fire and carried by people on a parapet above and behind the prisoners. A prisoner is loosed from his chains. First he sees the carved images and the fire. Then he is led out of the cave into ‘the real’ world. Blinded by the light of the sun, he cannot look at the trees, rocks and animals around him, but instead looks at the shadows and reflections (in water) cast by those objects. As he becomes acclimatized, he turns his gaze to those objects and finally, fully acclimatized, he looks to the source of illumination, the sun itself.