428-348 B.C.

Greek philosopher

Plato was one of the most important philosophers* in history. A pupil of Socrates, he was the teacher of another great philosopher, Aristotle. Plato’s writings, consisting almost entirely of dialogues*, analyze a variety of philosophical issues including questions of ethics* and metaphysics*. His complex and thought-provoking work has served as a starting point for many philosophers who succeeded him. Plato founded a school, known as the Academy, that remained an important training ground for philosophers and scientists for centuries after his death. Some historians consider the Academy the world’s first university.

Plato's Life. Few details are known about Plato’s life. Both of his parents came from high-ranking, distinguished Athenian families. Plato grew up in an educated and cultured setting, with family connections to some of the most powerful figures in Athens. He may have studied with a philosopher named Cratylus, but the major influence on his life and thought came from Socrates, a longtime associate of Plato’s mother’s family. Plato probably was introduced to the older philosopher at an early age, and the two became close friends.

Although urged by his relatives to enter politics, Plato decided instead to devote his life to philosophy. Unlike Socrates, Plato did not believe that he had a duty to marry and raise a family of sons to swell the ranks of Athenian citizenry. After Socrates died, Plato left Athens and spent 12 years traveling. In Italy and Sicily, he met the followers of the mathematician and philosopher Pythagoras and learned of their belief that dreams and visions pointed the way to spiritual truth.

Around 387 B.C., Plato returned to Athens and founded the Academy with the intention of training future statesmen and politicians. He supervised the Academy until his death 40 years later. According to some sources, Plato was invited to Syracuse in Sicily in the 360s B.C. to train Dionysius II, the young man who had inherited the throne. Plato made two trips to Syracuse, but Dionysius resisted his teacher. Plato died in Athens and supposedly was buried in the Academy.

* philosopher scholar or thinker concerned with the study of ideas, including science

* dialogue text presenting an exchange of ideas between people

* ethics branch of philosophy that deals with moral conduct, duty, and judgment

* metaphysics branch of philosophy concerned with the fundamental nature of reality


Plato founded the Academy for the systematic study of philosophy and the sciences. The school soon became famous as a center of learning. All the leading mathematicians of the 300s B.C. were pupils of Plato. Rulers and citizen assemblies from many cities turned to the legal experts of the Academy for advice on kingship or for help in writing laws and constitutions. The Academy existed until A.D. 529, when the emperor Justinian closed it because it was not a Christian institution.

One of the great ancient philosophers, Plato created thought-provoking works that are still read and discussed today. His Academy— founded to explore issues such as ethics and metaphysics—is considered by many to be the first university.

The Dialogues. Plato left a record of his thought in a collection of writings called dialogues. Between 25 and 30 of the surviving dialogues are genuine works of Plato. These documents are in the form of conversations, almost like plays or stories, in which characters discuss philosophical issues by asking and answering questions. They test each other’s arguments and explore the strengths and weaknesses of opposing points of view. This method, which is sometimes called dialectic, reveals one of Plato’s fundamental beliefs. For Plato, the value of philosophy lay not in telling people what to think or how to act but in making them question, ponder, and eventually recognize the truth for themselves.

Plato himself does not participate in the dialogues. Instead, Socrates appears as the main character in most of Plato’s writings. This is especially true in Plato’s earlier dialogues, such as the Apology, which relates Socrates’ speech in his own defense at his trial. Unlike many philosophers, Plato never wrote a systematic explanation of his views. For these reasons, it is sometimes difficult to know whether a particular concept originated with Plato or with Socrates. Understanding Plato’s philosophy requires a careful analysis of the content of the dialogues.

In the dialogues, Plato raised a series of important questions and then showed how a thoughtful person might set about answering them. Some of those questions concern ethics. Plato often portrays Socrates exposing the ignorance of people who claimed to know what was right and true. For example, in a dialogue called Euthyphro, Socrates meets a man who claims to be a religious expert. By the end of the dialogue, Socrates has shown that Euthyphro cannot even define what piety, or religious devotion, truly means.

Other philosophical questions deal with metaphysics. Plato was always concerned with the question of how the truth can be perceived. He believed that wisdom meant understanding the eternal truths or realities of the universe. One of Plato’s most important concepts was that these truths, or realities, exist as ideals that he called Forms. We perceive something as cold, for example, because it embodies something of the quality or Form of absolute coldness.

Plato maintained that people had souls that did not die when the body died. The philosopher’s primary goal was to care for the soul, which would be reborn over and over again into new bodies until it achieved ultimate wisdom. The true philosopher did not fear death, which was simply the separation of the soul from its prison in the body. In his dialogue Timaeus, Plato presented his belief that the universe was created by a well-meaning god. Although evil existed, the universe was ultimately a place of goodness and order.

The Republic and the Laws are long dialogues that express Plato’s political ideas. Plato wrote in the Republic that states would not be well governed until kings became philosophers or philosophers became kings. He outlined the appropriate education for such a philosopher-king and also described the structure of the ideal state. Because Plato believed that the human soul had three parts—reason, emotion, and appetite (desire)—he believed that the state, too, should have three parts—rulers, the rulers’ helpers or guardians, and producers. Rulers were to the state what reason was to the soul—the part that knew what was best for all operated according to this expert judgment. When a soul was governed by reason, it was in a state of harmony. A state governed by reasonable philosopher-kings would also be in a state of harmony, which Plato equated with justice.

Plato's Influence. Plato’s influence on Western thought began during his lifetime and has continued to the present. Through his Academy, Plato influenced philosophers, politicians, writers, and scientists throughout the Greek world. He also influenced many Roman thinkers, especially the great Roman orator* Cicero. In the A.D. 200s, the Greek philosopher Plotinus combined Plato’s philosophy with Eastern mysticism* to form a new system of philosophy known as Neoplatonism.

After Plato’s writings were translated into Latin in the late 1400s, European philosophers studied Platonic ideas. Although Plato had lived centuries before the founding of Christianity, Renaissance* scholars believed that his philosophy did not clash with Christian beliefs. Interest in Plato increased during the 1800s. Some modern thinkers admire his ideas about education and about the human soul. Others, however, have pointed out that the ideal society and state that Plato described in the Republic and the Laws is really a dictatorship. (See also Philosophy, Greek and Hellenistic; Philosophy, Roman.)

* orator public speaker of great skill

* mysticism belief that divine truths or direct knowledge of God can be experienced through faith, spiritual insight, and intuition

* Renaissance period of the rebirth of interest in classical art, literature, and learning that occurred in Europe from the late 1300s through the 1500s

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