Plato is quite possibly the world’s best known and most widely read and studied philosophers. He was the student of Socrates and the teacher of Aristotle, and he wrote in the middle of the fourth century B.C.E. in ancient Greece. Though influenced primarily by Socrates, to the extent that Socrates is usually the main character in many of Plato’s writings, he was also influenced by Heraclitus, Parmenides, and the Pythagoreans. In this article I introduce the key ideas and thoughts that Plato presented throughout his life and are still important in philosophy today.


Plato’s Utopia:

  • In the first part of his most established dialogue, The Republic, Plato describes his utopia. A utopia is defined as “an imagined place or state of things in which everything is perfect.”
  • Plato’s ideal commonwealth consisted of three classes: common people, soldiers and guardians (the only ones with any political power).
  • He held very strict views, and these were to be proposed through educational, biological, religious and economic schemes.
  • Education would be divided into two parts, music and gymnastics. Music is taken to be anything in the region of muses and gymnastics, anything to do with physical training and fitness.
  • There would also be severe censorship from an early age over literature and music. Mothers and nurses were only allowed to tell authorized stories. For example, Homer and Hesiod stories were forbidden as they represented the gods behaving badly occasionally.  The young were taught that God is only the creator of God things.
  • Regarding economics, wealth and poverty were regarded as harmful and neither would exist. Guardians were to live in small houses and eat simple food. There was to be no private property and gold and silver would be forbidden.
  • Culture was allocated to making men gentlemen and women would have complete equality with men.
  • Only the government had the prerogative to lie. There was “One Royal Lie,” and that was that god had created the three classes of men.
  • Justice consisted of everyone fulfilling their own work and not interfering with that of the other classes.
  • Although Plato’s Republic would achieve success in wars against equal populations and would  always provide nutritionally for the nation, no art or science would be offered because of the severity of his laws.


Plato’s Theory of Ideas

  • This theory is approached in the middle section of The Republic and focuses on philosophy rather than politics. His philosophy depends heavily on the differentiation between appearance and reality.
  • His main focus was to answer the question: What is a philosopher? By doing this he would explain why he believed they had the right to rule.
  • For Plato, Philosophy was the “vision of truth.” A classic example of this was his idea that a man who loves beautiful things is not a philosopher as it is relies on dreaming and opinion. However, a man who loves beauty in itself, uses knowledge and is therefore a philosopher.
  • His theory of ideas, part logic and part metaphysics, helped to explain this idea.
  • The logic side focused mainly on the meaning of general words that language could not function without. For example, “chair.”
  • The metaphysical side focuses on these general words referring to a certain ideal form created by God
  • Plato believed that when a number of individual items have a common name they also have a common “idea” or “form.”
  • He argued that although there are many chairs, for example, there is only one true “form” of a chair and the rest are therefore unreal, only copies of the first idea.
  • The one real chair is made by God, but only philosophers have knowledge of this one ideal form. People destitute of philosophy only understand the apparent forms.

The Parable of the Cave

  • Plato uses his analogy of the cave to explain his theory of ideas/forms.
  • Those who are devoid of philosophy are compared to prisoners in a cave. These prisoners are tied by chains (which arguably represent the physicality which we are bound by) and are therefore only able to see in one direction.
  • There is a fire behind them and a wall in front. All the prisoners can see is the shadows of themselves and of objects behind them reflected on the wall by the light of the fire.
  • All of the prisoners consider these shadows to be real.
  • One man escapes from the cave and is overwhelmed by the Sun. The Sun represents enlightenment and God. For the first time, he sees real things but he is confused and wants to return to the cave. However, once he returns he cannot believe that the shadows are real but none of the other prisoners believe him.
  • The cave explains the delusion of what people on earth see and believe to be real. But once you have been enlightened, you can never return to the false knowledge.
  • The escaped prisoner arguably represents a philosopher. Plato believed that only philosophers have enlightened ideas of the “forms,” and that this is why they should rule.

Following Criticism’s

  • The differentiation between knowledge and opinion. If knowledge is infallible and opinion can be mistaken, you cannot have opinion of something that is not but it cannot be of what it is because that would make is knowledge. Plato satisfies this contradiction with the idea that there are intermediates between being and not being, his conclusion being that opinion connects with the senses and knowledge with the eternal world.
  • But in connection with his parable of the cave, how can a conceptual world be more real than a physical world that you experience through senses?
  • Is there a perfect form for everything? Even a negative emotions such as sadness? Or a subjective feeling like beauty?
  • From the Christian point of view, one may question why God was not happy with the world of ideas and created the cave. However, Plato may respond to this by explaining that God only created what is good and so was not responsible for the cave.
  • Bertrand Russell points out that Plato has no real understanding of philosophical syntax. According to Russell, he fails to establish the gap between universals and particulars.
  • Despite these criticisms, however, Plato’s theory of ideas did allude to an important advance in philosophy. It emphasizes the problem of universals which is still an issue today. It uses a good combination of logic (alluding to Parmenides, the ancient Greek philosopher) and other-worldliness (touching on Pythagoras) This combination was both satisfying to intellectual and religious emotions and thus was influential to many great philosophers.

Plato’s Theory of Immortality

  • After the death of Socrates, Plato reconstructed Phaedo (one of Socrates’ many dialogues).
  • This dealt with immortality of the soul.
  • According to Socrates, and thus Plato, death was regarded as the liberation of the soul. Socrates defined death as the separation of the soul and the body.
  • He believed that throughout our lives, desires and needs of the body are permanently hindering us from furthering our philosophy.
  • We are slaves to our bodies’ emotions and are constantly distracted with looking after ourselves. Therefore, there is no time for philosophy.
  • If we want pure knowledge, we must reject the body and scrutinize things through the soul.
  • Thus, philosophers must have as little association with the body as possible. The ultimate goal being independence of the body so they can achieve higher knowledge and understanding.
  • Conclusively, death should not be feared but embraced by philosophers as it is the only condition where we are independent of the the body.

Plato’s Cosmology

  • Plato discusses his cosmogony in Timaeus, one of his many dialogues.
  • Plato first begins his cosmogony argument with: “everything that becomes or is created must…be created by some cause.”
  • He questions whether this can be applied to the universe and concludes that it does. Therefore, the world is not perpetual, but must have been created.
  • If this is the case, the world must have a creator. However, Plato has very little interest in who this creator may or may not be as he is more interested in the nature of the universe, rather than its origins.
  • According to Plato, the world is a “copy of something,” something being the creator. The creator is void of jealousy and “desired that all things should be as…himself.” Therefore, the world represents the creator.