Plato was born around 427 b.c. into one of the most prominent families in Athens. As a youth, he found himself drawn to the enigmatic figure of Socrates, an ugly man of no particular wealth or prominence who wandered about the open places of Athens, engaging his fellow citizens in debate. Plato was enraptured by this peculiar man’s ability to reduce the most pompous and self-confident aristocrats to a state of bewilderment, and he became Socrates’ student.
Plato’s family and friends expected him to pursue a political career, but a combination of events turned him decisively away from politics and into philosophy. He came of age during the Peloponnesian War between Athens and Sparta, the two superpowers of the ancient Greek world. The war ended in total defeat for Athens in 404. Sparta imposed a dictatorship of thirty tyrants, some of whom were Plato’s relatives and Socrates’ fellow students. The tyrants proved to be a corrupt lot and were soon removed, and Athenian democracy was restored. The new democratic government of Athens tried Socrates on charges of impiety and corrupting the youth of Athens, and they executed him in 399. Prompted by the failure of his own relatives to properly govern Athens, as well as by the failure of Athenian democracy as evidenced by its persecution of Socrates, the young Plato turned his back on the public life that awaited him.
Inspired by Socrates’ example, Plato turned to philosophy. In honor of his beloved teacher, Plato wrote dialogues, recording the kinds of conversations Socrates had in public with his fellow Athenians. Around 388, Plato traveled to Syracuse in Sicily, where he studied Pythagorean philosophy. Soon after his return to Athens, he founded the Academy, where he and like-minded thinkers discussed philosophy and mathematics. Aristotle was among the young students who came to learn from Plato. The Academy lasted in one form or another until a.d. 527 and has served as the prototype of the Western university system.
Plato spent the rest of his life at the Academy, except for two more visits to Syracuse in a failed attempt to mold that city’s young tyrant into an ideal philosopher-king. The dialogues he wrote as a mature philosopher still mostly feature Socrates as the protagonist, but it may well be the case that many of the views discussed in these dialogues belong to Plato and not to the historical Socrates. Plato died in Athens at the age of eighty, duly recognized as one of the world’s great philosophers.
Plato was born at the tail end of one of the brightest periods of any civilization in world history. Athens became the most prominent of the Greek city-states after leading the defense of Greece against the mighty armies of the Persian Empire in the first half of the fifth century b.c., and its large navy made Athens a prosperous trading port. The Athenians used their wealth to build a city of architectural marvels and celebrated their shared humanity in dramatic festivals featuring plays that are still performed today. Though the city relied on slave labor and treated women as second-class citizens, it was remarkably democratic. Every male citizen had an equal say in the government of the city, and they met regularly in a large assembly to debate policy.
The golden age of Athens came to a tragic end in the Peloponnesian War, but Plato’s Athens of the fourth century b.c. held on to many of its proud traditions. Throughout Plato’s life, Athens was the cultural and intellectual center of the Greek world. People would travel from great distances to seek fame and fortune in Athens or to study at the feet of one wise teacher or another.
Plato lived in a transitional period, both for Athens and for Greek civilization generally. As literacy became widespread among the educated classes, a new kind of thinking evolved. The Greeks started recording their history and philosophy, which allowed them to think critically about their past and their inherited wisdom. Religious rituals and myths about gods and titans seemed less convincing in this new worldview, and so a whole set of traditional values fell into doubt. Itinerant sophists traveled from city to city, preaching that morals are relative and offering to instruct young statesmen in the art of rhetoric and debate for a fee. Meanwhile, philosophers, no longer satisfied by the traditional explanations offered by myths, began searching for rational explanations of the world and our place in it. This search gave birth to the Western study of mathematics, science, psychology, and ethics, among other subjects.
Socrates was Plato’s greatest philosophical influence. He taught Plato the intellectual humility of recognizing that our supposed wisdom amounts to nothing when carefully scrutinized. To that end, Socrates also inspired Plato by exhibiting an unprecedented level of scrutiny to the assumptions and prejudices of his age. Socrates’ penetrating mind always aimed at the heart of a given matter, insisting that the people he debated with give precise definitions of the terms they used.
The sophists used a similar question-and-answer method that reduced their opponents to perplexity, but they did so to score rhetorical points rather than to seek the truth. Many of these sophists, most notably Protagoras, were respected philosophers in their own right. Protagoras is most famous for his Measure Doctrine that “man is the measure of all things.” He believed that truth is relative and that whatever seems so to a person is so for that person. Plato’s investigations of virtue aim precisely at replacing this dangerous relativism with a solid basis for moral values.
Plato’s studies in philosophy put him in contact with the ideas of previous generations, particularly those of Pythagoras. Pythagoras is a semimythical figure, credited with being the first mathematician. He had a secretive, cultlike following that worshipped numbers and identified mathematical harmony as the basis of reality. Plato was impressed with the power of mathematics and reportedly once disappointed a large crowd that had come to hear him lecture on the Good by speaking only about mathematics. Plato also inherited the Pythagorean belief in reincarnation.
Plato tried to reconcile the opposing views of Heraclitus and Parmenides over the question of whether everything is in flux or whether all change is an illusion. Heraclitus advocated the former of these two views and was famous for his claim that one could never step into the same river twice. Parmenides and his follower Zeno believed reality was a single, unified, unchanging being and that any appearance of change is an illusion. Zeno formulated a perplexing series of paradoxes to challenge anyone who believes that motion is possible. Plato’s Theory of Forms can be understood as a synthesis of the views of Heraclitus and Parmenides. He explains that the physical world is inconstant and always changing, as Heraclitus supposed, but that above the physical world is a world of Forms that is constant and unchanging, as Parmenides supposed.
Plato’s influence would be difficult to overestimate. It would not be an exaggeration to say that Plato is primarily responsible for inventing what people in the West think of as “thought.” Plato succeeded in formulating his ideas into a general approach to thought that emphasizes dialogue, critical thinking, and an appreciation of the power and distinctiveness of abstract ideas. The only other philosopher who has had an influence to rival Plato’s is Aristotle, and Aristotle cut his philosophical teeth at Plato’s Academy.