Plato

 

Plato believed in two worlds: the material world and the world of ideas. The material world is merely an imitation of the eternal world of ideas. Let me illustrate this. Surely no two horses are exactly similar, yet they all have something in common: they are horses. Plato believed that there must exist a perfect "idea" of a horse in the world of ideas, and all horses in the material world are imperfect copies of that ideal form.

In this regard, Plato agreed with Heraclitus. He believed that everything in the material world flows and changes, but unlike Heraclitus, he thought there existed a permanent reality beyond it. While the material world is in constant flux, the world of ideas is eternal and unchanging.

Plato explained this through his famous cave metaphor. Imagine three men born in a cave facing a wall. Behind them is a fire, and between the fire and the prisoners objects are moved, casting shadows onto the wall. Since the prisoners have never seen anything else, they believe the shadows are reality itself.

Suppose one of the men frees himself and leaves the cave. For the first time he sees the real world and a real horse rather than merely its shadow. He is dazzled by what he sees. Eventually he realizes that the shadows in the cave were only poor imitations of reality. Instead of enjoying his freedom, however, he returns to the cave to tell the others what he has discovered. The cave dwellers refuse to believe him and ultimately kill him.

Plato believed that the world of the senses is temporary and unreliable. We can only have inexact conceptions of things we perceive through our senses. True knowledge comes not from observation but from understanding with the mind. It is therefore no surprise that Plato was drawn to mathematics, since mathematical truths appear eternal and unchanging.

According to Plato, the soul is immortal. The soul existed before it inhabited the body. However, once it awakens within a body, it forgets the perfect ideas it once knew. As a person encounters beauty, truth and wisdom, a vague recollection begins to stir within the soul. Learning is therefore not acquiring new knowledge but remembering what the soul once knew. The soul must free itself from the chains of the body and return to the world of ideas. Plato considered this the philosopher's path.

Plato's ideal state, often called a utopia, would be governed by philosophers. Since philosophers seek truth rather than wealth or power, he believed they would be the best rulers.

Plato also divided the soul into three parts. Reason is responsible for rational thinking and should govern the individual. Spirit consists of emotions such as courage, pride and anger. Appetite consists of desires such as food, pleasure and wealth. A just person is one in whom reason controls spirit and appetite, creating harmony within the soul.