(ca. 428/427 – 348/347 B.C.E.)
Greek Philosopher

Portugees version



  • Studied philosophy in Athens under Socrates, 408-400 B.C.E.


  • Ca. 387, established the Academy of Athens, taught philosophy there for 40 years

Ideas and Contributions

Plato was born into a wealth Athenian family and planned to become a politician. As he grew older, he became repulsed by the brutal and unethical practices of Athenian dictators. In 399 B.C.E. he left Athens when his friend Socrates was sentenced to death. Twelve years later, he founded a school of philosophy and science called the Academy, the first university. Plato is famous for his written dialogues, conversations between two or more characters debating philosophical issues. His earliest dialogues utilize Socrates as the main character who questions others on their beliefs and ideas. (World Book)

Plato’s philosophy was based on his theory of a soul divided into three components, reason, will and appetite. He contended that one can identify the parts of the soul because they sometimes clash with each other. A person may crave or have an appetite for something, yet resist the craving with willpower. A correctly operating soul requires the highest part, reason, to control the lowest part, appetite, with assistance from the will.

Plato regarded the body and soul as separate entities. As a dualist, he also posited an “unreal” world of the senses and physical processes, and a “real” world of ideal forms.

Plato believed that though the body dies and disintegrates, the soul continues to live forever. After the death of the body, the soul migrates to what Plato called the realm of the pure forms. There, it exists without a body, contemplating the forms. After a time, the soul is reincarnated in another body and returns to the world. But the reincarnated soul retains a dim recollection of the realm of forms and yearns for it. . . . In the Meno, Plato has Socrates teach an ignorant slave boy a truth of geometry by simply asking a series of questions. Because the boy learns this truth without being given any information, Plato concluded that learning consists of recalling what the soul experienced in the realm of the forms. (World Book, p. 570)

Plato thought that only the soul could perceive the ideal forms. When the body and the soul combine, the body obstructs the soul’s ability to recall the ideal forms. “Knowledge is not given by the senses but acquired thought them as reason organizes and makes sense out of that which is perceived ( Zusne, p. 6).” Reason unveils the ideal forms behind appearances.

Plato’s philosophy was influential in the development of early Christian thought through the ideas of Plotinus [ca. 205-270, Roman philosopher who developed Neoplatoism, a philosophy based on Plato’s ideas] and the writing of St. Augustine. The idea of the separation of the body and soul, and an immortal soul also began with Plato. During the 13th century, Aristotle’s ideas replaced Plato’s ideas as the most influential philosophy in Christian thought.


  • The Sophist
  • The Symposium

References: 27, 29