Summarize the allegory of the cave

There are a number of summaries available, simply follow the links below;

http://www.historyguide.org/intellect/allegory.html

In the allegory of the cave, Plato asks us to imagine the following scenario: A group of people have lived in a deep cave since birth, never seeing any daylight at all. These people are bound in such a way that they cannot look to either side or behind them, but only straight ahead. Behind them is a fire, and behind the fire is a partial wall. On top of the wall are various statues, which are manipulated by another group of people, laying out of sight. Because of the fire, the statues cast shadows on the wall that the prisoners are facing. The prisoners watch the stories that these shadows play out, and because this is all they can ever see, they believe that these shadows are the most real things in the world. When they talk to one another about “men,” “women,” “trees,” “horses,” and so on, they refer only to these shadows.

Now he asks us to imagine that one of these prisoners is freed from his bonds, and is able to look at the fire and at the statues themselves. After initial pain and disbelief, he eventually realizes that all these things are more real than the shadows he has always believed to be the most real things; he grasps how the fire and the statues together caused the shadows, which are copies of the real things. He now takes the statues and fire as the most real things in the world.

Next this prisoner is dragged out of the cave into the world above. At first, he is so dazzled by the light in the open that he can only look at shadows, then he is able to look at reflections, then finally at the real objects—real trees, flowers, houses, and other physical objects. He sees that these are even more real than the statues were, and that those objects were only copies of these.

Finally, when the prisoner’s eyes have fully adjusted to the brightness, he lifts his sights toward the heavens and looks at the sun. He understands that the sun is the cause of everything he sees around him—of the light, of his capacity for sight, of the existence of flowers, trees, and all other objects.

The stages the prisoner passes through in the allegory of the cave correspond to the various levels on the line. The line, first of all, is broken into two equal halves: the visible realm (which we can grasp with our senses) and the intelligible realm (which we can only grasp with the mind). When the prisoner is in the cave he is in the visible realm. When he ascends into the daylight, he enters the intelligible.

The lowest rung on the cognitive line is imagination. In the cave, this is represented as the prisoner whose feet and head are bound, so that he can only see shadows. What he takes to be the most real things are not real at all; they are shadows, mere images. These shadows are meant to represent images from art. A man who is stuck in the imagination stage of development takes his truths from epic poetry and theater, or other fictions. He derives his conception of himself and his world from these art forms rather than from looking at the real world.

When the prisoner frees himself and looks at the statues he reaches the next stage in the line: belief. The statues are meant to correspond to the real objects of our sensation—real people, trees, flowers, and so on. The man in the cognitive stage of belief mistakenly takes these sensible particulars as the most real things.

When he ascends into the world above, though, he sees that there is something even more real: the Forms, of which the sensible particulars are imperfect copies. He is now at the stage of thought in his cognition. He can reason about Forms, but not in a purely abstract way. He uses images and unproven assumptions as crutches.

Finally, he turns his sights to the sun, which represents the ultimate Form, the Form of the Good. The Form of the Good is the cause of all other Forms, and is the source of all goodness, truth, and beauty in the world. It is the ultimate object of knowledge. Once the prisoner has grasped the Form of the Good, he has reached the highest stage of cognition: understanding. He no longer has any need for images or unproven assumptions to aid in his reasoning. By reaching the Form of the Good, he hits on the first principle of philosophy which explains everything without the need of any assumptions or images. He can now use this understanding derived from comprehending the Form of the Good to transform all his previous thought into understanding—he can understand all of the Forms. Only the philosopher can reach this stage, and that is why only he is fit to rule.

Plato is unable to provide direct detail about the Form of the Good, and instead illustrates his idea by comparing it to the sun. The Form of the Good is to the intelligible realm, he claims, as the sun is the visible realm. (In the metaphor, the fire in the cave represents the sun.) First of all, just as the sun provides light and visibility in the visible realm, the Form of the Good is the source of intelligibility. The sun makes sight possible, and, similarly, the Form of the Good is responsible for our capacity for knowledge. The sun causes things to come to be in the visible world; it regulates the seasons, makes flowers bloom, influences animals to give birth and so on. The Form of the Good is responsible for the existence of Forms, for their coming to be in the intelligible world.