e four segments of the line. Imagination is when the cave man is still in the cave, watching only the shadows of things against the wall. Belief is when the cave man has left the cave and is starting to look around, although his eyes are not yet accustomed to the Sun. Thought is when the cave man is able to look at things in the light of the sun, and try to come to an understanding of their true nature. It is the understanding of the cave man when, finally, he is able to look up at the Sun itself and see the light it shines. Once one is ready to look up at the Sun, and bask in the splendorous light of the Good, one understands the unity that brings the Forms of all things together. In short, Plato's cave allegory unveils the heart of his philosophy. The Good--as symbolized by the sun--is not only the source of all other essence and existence, but is the foundation of all knowledge. Because it grounds my knowledge of the world it also, if truly grasped, is the necessary and sufficient cause of my becoming virtuous and happy. To leave the cave and come to know the Good is then the goal of the philosopher's life. If it is accomplished, the philosopher not only knows the Good, but he becomes Good. By becoming virtuous, he becomes happy. ...
