1. Plato uses the allegory of the cave to distinguish between appearance and reality, and to explain the process of enlightenment.
2. In the allegory, prisoners chained in a cave see only shadows on the wall from objects being manipulated outside, mistaking these shadows for reality.
3. When one prisoner escapes and sees the true objects and sunlight, he comes to understand the limitations of sense perception and gains true knowledge, though his enlightenment makes him an outcast upon returning to the cave.