Plato was born in Athens in 428 BCE to an aristocratic family. Ancient sources claim that his father, Ariston, was a descendant of Codrus, the last king of Athens, and his mother, Perictione, of Solon, an almost mythical Athenian lawgiver and the author of the city’s first constitution. Plato’s two brothers, Glaucon and Adeimantus, appear as two of the main characters in The Republic.
Ariston died during Plato’s boyhood, and Perictione remarried Pyrilampes, a friend of the Athenian statesman Pericles. With his noble birth and intellectual talents, young Plato had fine prospects in Athenian politics. The political upheavals of his youth attracted him to the public sphere.
Two major upheavals turned Plato away from politics. The first was the assumption of power by two groups—the Four Hundred and the Thirty. These factions of wealthy citizens seized control at the end of the Peloponnesian War and turned Athens into an oligarchy. Plato had mixed feelings about the takeover. He was related to Charmides, a member of the Thirty. But his nascent rational outlook made him critical of the government for its tyrannical leanings and instability. He was active in supporting the restoration of democracy, but that system proved itself less than perfectly just in 399 BCE. In that year, Plato’s mentor, Socrates, an eccentric philosopher and a cult figure among the Athenian youth, stood before a jury of about 500 Athenians on charges of not recognizing the gods of the state, of inventing new deities, and of corrupting the youth of Athens. More than these charges, Socrates’s close association with a number of men who had fallen out of political favor in Athens brought him to trial. Because an amnesty had been declared for political offenders, other charges had to be brought against him. Socrates was found guilty by a narrow margin and sentenced to death.
After Socrates’s death, Plato devoted himself to continuing the work of his teacher. He spent years traveling around the Mediterranean, teaching and learning. Among the places he visited was Sicily, the center of Pythagorean thought. In 387 BCE, Plato resettled in Athens and founded the Academy, probably the first institution of its kind, and the model for the Western university. Plato and other teachers instructed students from all over the Mediterranean in metaphysics, epistemology, ethics, politics, and the natural and mathematical sciences. Although the Academy was not meant to prepare students for any sort of profession, such as politics, law, or medicine, the topics taught there were not divorced from the larger world. Members of the Academy were invited by various cities to aid in the development of new constitutions. The Academy lasted in one form or another until CE 527, 912 years in total. Plato spent the rest of his life as the director of studies at the Academy, although it is not at all clear that he himself taught there. He is thought to have written The Republic there in around 380 BCE. The most famous student of the Academy during this time was the philosopher Aristotle.
From 385 BCE until his death in 347, Plato only left the Academy twice, both times to visit Sicily. What drew him away from his school was the possibility of putting the political theory he outlined in The Republic into practice. In 367 BCE, Dionysus I, tyrant of Sicily, died. His brother Dion, father of the heir, had been a student of Plato’s and immediately sent for his teacher. Unfortunately, Dionysus II remained unconvinced that the vigorous study of mathematics and philosophy would be the best preparation for his rule, and so the world lost its chance to test the first philosopher-king.
Philosophy first emerged in the sixth century BCE on the Greek island of Miletus. The first philosophers focused on questions of natural science, trying to explain the world that they observed around them in terms of a few simple principles. Little attention was given to issues in ethics and politics. Poets, not the philosophers addressed the values of the society. Poets like Hesiod and Homer outlined the virtues that marked the good Greek man. They found motivation for good behavior in the promise of divine reward.
In the fifth century BCE, two tremendous political upheavals cast traditional Greek values into question and thrust issues of ethics into the hands of the philosophers. From 431 to 404 Athens and Sparta were engaged in the Peloponnesian War, which Athens finally lost. The ravages of war cast doubt on the martial virtues of Homeric heroes, and the growth of democracies, especially in Athens, called for new civic virtue: the ability to speak persuasively in the assemblies and law courts became more valuable than warcraft.
In this Athenian climate a new class emerged: the Sophists, itinerant teachers who would offer instruction in nearly any subject if the student was willing and able to pay a fee. Their focus was on rhetorical skills, and they emphasized the primacy of persuasiveness over truth. The Sophists exploited the new uncertainty about traditional moral values. There was no cohesive school of Sophism, and the views of teachers varied widely. What we know of their thought indicates that they frequently claimed that whether or not an action is right or wrong is less important than whether or not it benefits the interests of the agent. Many argued that there were no such things as right and wrong—that objective moral standards did not exist. Some denied any possibility of objective truth and scoffed at the idea of objective knowledge. They claimed that morality is a convention imposed by the rulers of societies upon their subjects. In The Republic, the Sophist Thrasymachus declares that immorality is a virtue because it enables us to advance in the competition of life. In Plato’s dialogue the Gorgias, an even stronger view is attributed to a man named Callicles; he claims that conventional morality is unjust because it attempts to deprive the strong of their natural right to exploit the weak. While some Sophists, such as Hippias, were adamant in their refusal of such doctrines, we have reason to believe that the trend toward a belief in justice as the interest of the stronger was strong among Sophists.
In this moral climate, Socrates was motivated by a desire to combat what he viewed as forces creeping against morality. Socrates was disturbed by what he perceived to be the moral complacency of the Athenian citizens; he watched with concern as they lived their lives in a selfish, unreflective haze, focusing on gaining and increasing their own power and using the theories of the Sophists to justify their attitude. His solution was to act as a “gadfly,” stinging his fellow citizens into moral self-examination. He stood in the marketplace daily, trying to engage anyone he could in conversation. The unexamined life, he declared, was not worth living, and so he would force everyone he encountered to reflect on their lives, their beliefs, and their motivations.
Plato took over this mission when Socrates died. He too wanted to combat immorality and selfishness, which were still widespread. He also wanted to combat the Sophists’ other skeptical claims: their avowal that there is no such thing as objective truth, no possibility of objective knowledge.
Plato’s dialogues are classed into early, middle, and late periods. The early dialogues, written soon after Socrates’s death, provide the nearest portrayal of what Socrates’s philosophy might have been. In these dialogues, Plato focuses almost exclusively on ethical questions, using the Socratic method of elenchus. In a typical early dialogue, Socrates asks his interlocutor for a definition of some virtue (piety, courage, etc.); once the definition is offered, he shows that the definition is inconsistent with other beliefs that the interlocutor holds. The interlocutor refines his definition, and Socrates shows that the new version is still inconsistent with other beliefs. This cycle of revisions and rebuttals is intended to continue until a satisfactory definition is reached, but this never actually happens in any of the dialogues. With the exception of a few key doctrines, no idea ever emerges from elenchus still looking tenable. A typical early dialogue ends in a state of aporia—intellectual gridlock, where all existing beliefs on the topic have been rebutted, but progress seems impossible. The interlocutors know what they thought before was wrong, but they are not told what to believe instead.
These dialogues should not be considered failures. According to Socrates, the goal of elenchus is not to reach definitions. He claimed that engaging in philosophic dialectic is crucial to human well-being—rendering people both happier and more virtuous. He believed this so strongly that, by some accounts, he chose to be executed rather than give up the practice. Though in the early dialogues Plato utilizes Socratic methods, he does not accept everything taught to him by Socrates. He explores many of these views critically, laying them out but not necessarily endorsing them.
In the middle period, Plato develops a distinct voice and philosophical outlook. The figure of Socrates becomes more of a mouthpiece for Plato’s own views. He relies less on the method of elenchus and presents his dialogues as conversation between a teacher and his students rather than as debate between a philosopher and his opponents. Instead of aporia, interlocutors arrive at positive conclusions. Ideas hinted at in the early dialogues, such as the theory of Forms, emerge as full-fledged doctrines. Plato’s interests broaden beyond ethics into epistemology and metaphysics. He draws on his theory of Forms and the idea of the soul to explore old questions about how to live, the nature and role of love, and the nature of the physical world.
The theory of Forms grounds most of the other theories Plato puts forward in his middle period. It is also his response to the challenge of the Sophists and their claim that there is no objective truth, moral or otherwise. The theory of Forms proposes that in addition to the physical world we sense around us, there is another realm of reality. This realm, a purely intelligible rather than observable sphere of existence, is made up of eternal, absolute, unchanging, perfect Forms which define all that exists fleetingly and imperfectly in the world of our senses. The Forms provide knowledge of objective truth.
The Republic is paradigmatic of the shift from the early to middle periods. Book I adhers to the structure of a typical early dialogue. Some speculate that it originally stood on its own as a dialogue dating from the early period (in which case it would have been called Thrasymachus). Plato has Socrates use the method of elenchus in an attempt to pry out a definition of justice, and the result is aporia. Instead of leaving off there, Socrates picks up the question in Book II. He hashes out a detailed positive theory of justice over the course of nine more books. In these books, rather than employing the elenchus, Socrates mostly lectures, pausing intermittently to respond to objections raised by his students, Plato’s two brothers. In Book VII, Socrates warns against elenchus. He declares that philosophical dialectic is dangerous in the wrong hands and should only be taught to the right people and only then when they are old enough to use it properly. He warns that those without the proper respect for truth would use the method in order to argue against everything instead of using it to seek out what is right. This discussion might explain what motivated Plato’s shift in methods of inquiry and what motivated him to found the Academy.
The later dialogues are extremely difficult and controversial. They contain Plato’s most complex philosophical and logical views, and there is little agreement over what trends and themes define this period. One work among this later group is worth mentioning in relation to The Republic. In the Laws, possibly Plato’s last work, he constructs another ideal state. Though this state too is authoritarian, it has democratic elements and differs vastly from the state portrayed in The Republic. Plato grew more willing to compromise principles in order to find something that might work in practice. He came to emphasize the value of the rule of law, whereas in The Republic he suggested that law was unnecessary in a city with the right rulers.