The contributions of Plato to the western civilization and philosophy.

Metaphysics:

Plato's greatest contribution to modern society is found in his theories relating to metaphysics. These is now referred to as Platonism (or Exaggerated Realism). Plato divides his world into two aspects: the intelligible world and the perceptual world.

The Perceptual world: Plato saw the perceptual world around us as imperfect copies of the intelligible forms or ideas.

The Intelligible world: Forms are unchangeable and perfect, and only comprehensible by the use of intellect and understanding. For example, a triangle belongs to the world of forms, since we can reason out its properties (angles always equal to 180 degrees, for example), using our intellect. Imagination, though, is part of the perceptual world, since it is not concrete and unchanging for each person.

Nature of Knowledge and Learning:

Plato's ideas on knowledge has survived throughout the ages and is still relevant in today's society. Today it has come to be known as Platonic epistemology.

Platonic Epistemology: Plato believed that knowledge is innate, or inborn, and that the development of ideas buried deep in the soul, and may be guided out by teachers. Plato drew a sharp distinction between knowledge, which is certain, and mere opinion. Opinions derive from the shifting world of sensation -- knowledge derives from the world of timeless Forms, or essences.

The Analogy of the Cave: In his best-known dialogue, "The Republic", Plato drew an analogy between human sensation and the shadows that pass along the wall of a ca ve. He tells his audience to imagine a group of people tied up, facing the wall of a cave. They are unable to move, and see only the shadows of the real objects. Supposing a prisoner was taken from the cave and shown the real world. At first he would doubt what he saw, preferring his earlier knowledge. Slowly, though he would come to understand the true knowledge of the world.

Through this allegory, Plato is exemplifying the difference between opinion (the distorted shadows on the wall), and knowledge (the true world outside the cave)

The Divided Line: Making use of both the above theories is Plato's Divided Line. Everything in the universe fits onto a line which increases in reality. It is divided into quarters. The first half represents the intelligible world, and the second, the perceptual worlds. Each of these worlds are again cut in half.

The perceptual world is divided into tangible objects, followed by shadows, reflections, and representations. Similarly, the intelligible world is divided into principles and most general forms, and derivative, "reflected" forms.

The diagram shows this idea, and how each section, starting from A and ending at E, increases in reality.

Democracy and the Republic:

Plato was greatly critical of the Democratic government in which he lived. This is not surprising, perhaps, since, under a democratic system, his teacher, Socrates was put to death. He also came from a wealthy family and, Athens having been ruled by as an oligarchy (ruled by the upper class) until a bloody uprising in his early twenties, he might have resented the democratic movement for usurping his right to greater political freedom. On the other hand, the rule of the oligarchy was brutal and selfish, so Plato set out to find an alternative to either form of government. This is the reason for his most major work, "The Republic".

The Tripartate Soul: Plato believed that the government should be like the soul of mankind. He believed each person is made up of three layers: The lowest layer of the soul consists of the basic appetites and instincts, such as hunger, thirst, sex drive, sensual cravings, and the desire for material possessions. This translated to the common working class citizen of a city.

The second layer is made up of the "spirited" emotions, such as courage, anger, or ambition. They motivate a person to aim at higher things than the gratification of basic desires. The ambition to excel as a military commander or civic leader would be typical examples. This would be paralleled to the middle class, or military citizen.

The final and top layer of the soul is reason, the main interest of which is the acquisition of knowledge and understanding. Reason enables a person to deliberate and to contemplate things with detachment and objectivity; reason effects a certain distance between a person and his or her immediate desires and driving emotions. This layer is synonymous with the highest level of citizen; the citizen that lives for the ultimate gain of knowledge: as Plato called them, the Lovers of Wisdom, or Philosophers.

For a soul to be healthy and "just", the first two layers should be balanced. It is reason, though, that has to maintain ultimate control of all parts of the soul. In the same way, the two lower classes of a city (or country) have to remain balanced, but the Philosophers have to guide them.

In "The Republic", he outlines a new form of government, ruled not by the masses (as in democracy), not by the aristocracy (as in oligarchy, or monarchy), but by the intellectuals, or, as he called them, Lovers of Wisdom, or Philosophers. This system of government was very strict, aiming to dissuade ties of kinship and to weed out anyone not worthy of the Philosopher's life.