Plato (Greek: '''', Plátōn, "wide, broad-browed") (428/427 BC – 348/347 BC), was a Classical Greek philosopher. Together with his teacher, Socrates, and his student, Aristotle, Plato helped to lay the philosophical foundations of Western culture. Plato was also a mathematician, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the western world. Plato was originally a student of Socrates, and was much influenced by his thinking as by what he saw as his teacher's unjust death.

Plato's brilliance as a writer and thinker can be witnessed by reading his Socratic dialogues. Some of the dialogues, letters, and other works that are ascribed to him are considered spurious. Interestingly, although there is little question that Plato lectured at the Academy that he founded, the pedagogical function of his dialogues, if any, is not known with certainty. The dialogues have since Plato's time been used to teach a range of subjects, mostly including philosophy, logic, rhetoric, mathematics, and other subjects about which he wrote.

The exact birthdate of Plato is unknown. Based on ancient sources, most modern scholars estimate that he was born in Athens or Aegina between 428 and 427 BC His father was Ariston. According to a disputed tradition, reported by Diogenes Laertius, Ariston traced his descent from the king of Athens, Codrus, and the king of Messenia, Melanthus. Plato's mother was Perictione, whose family boasted of a relationship with the famous Athenian lawmaker and lyric poet Solon. Perictione was sister of Charmides and niece of Critias, both prominent figures of the Thirty Tyrants, the brief oligarchic regime, which followed on the collapse of Athens at the end of the Peloponnesian war (404-403 b.c.e.). Besides Plato himself, Ariston and Perictione had three other children; these were two sons, Adeimantus and Glaucon, and a daughter Potone, the mother of Speusippus (the nephew and successor of Plato as head of his philosophical Academy). According to the Republic, Adeimantus and Glaucon were older than Plato. Nevertheless, in his Memorabilia, Xenophon presents Glaucon as younger than Plato.

According to certain reports of ancient writers, Plato' s mother became pregnant through a virginal conception: Ariston tried to force his attentions on Perictione, but failed of his purpose; then the ancient Greek god Apollo appeared to him in a vision, and, as a result of it, Ariston left Perictione unmolested. Another legend related that, while he was sleeping as an infant, bees had settled on the lips of Plato; an augury of the sweetness of style in which he would discourse philosophy.

Ariston appears to have died in Plato's childhood, although the precise dating of his death is difficult. Perictione then married Pyrilampes, her mother's brother, who had served many times as an ambassador to the Persian court and was a friend of Pericles, the leader of the democratic faction in Athens. Pyrilampes had a son from a previous marriage, Demus, who was famous for his beauty. Perictione gave birth to Pyrilampes' second son, Antiphon, the half-brother of Plato, who appears in Parmenides.

In contrast to his reticence about himself, Plato used to introduce his distinguished relatives into his dialogues, or to mention them with some precision: Charmides has one named after him; Critias speaks in both Charmides and Protagoras; Adeimantus and Glaucon take prominent parts in the Republic. From these and other references one can reconstruct his family tree, and this suggests a considerable amount of family pride. According to Burnet, "the opening scene of the Charmides is a glorification of the whole [family] connection ... Plato's dialogues are not only a memorial to Socrates, but also the happier days of his own family".

According to Diogenes Laertius, the philosopher was named Aristocles after his grandfather, but his wrestling coach, Ariston of Argos, dubbed him "Platon", meaning "broad" on account of his robust figure. According to the sources mentioned by Diogenes (all dating from the Alexandrian period), Plato derived his name from the breadth (platutês) of his eloquence, or else because he was very wide (platus) across the forehead. In the 21st century some scholars disputed Diogenes, and argued that the legend about his name being Aristocles originated in the Hellenistic age.<b>

Apuleius informs us that Speusippus praised Plato's quickness of mind and modesty as a boy, and the "first fruits of his youth infused with hard work and love of study". Plato must have been instructed in grammar, music, and gymnastics by the most distinguished teachers of his time. Dicaearchus went so far as to say that Plato wrestled at the Isthmian games. Plato had also attended courses of philosophy; before meeting Socrates, he first became acquainted with Cratylus (a disciple of Heraclitus, a prominent pre-Socratic Greek philosopher) and the Heraclitean doctrines.

Plato may have traveled in Italy, Sicily, Egypt and Cyrene. Said to have returned to Athens at the age of forty, Plato founded one of the earliest known organized schools in Western Civilization on a plot of land in the Grove of Hecademus or Academus. The Academy was "a large enclosure of ground which was once the property of a citizen at Athens named Academus... some, however, say that it received its name from an ancient hero" , and it operated until 529 AD, when it was closed by Justinian I of Byzantium, who saw it as a threat to the propagation of Christianity. Many intellectuals were schooled in the Academy, the most prominent one being Aristotle.

Plato made himself seem as though he were part of the Socratic entourage but never says so explicitly. In the ''Phaedo'' the title character lists those who were in attendance at the prison on Socrates' last day and says "Plato was ill" (''Phaedo'' 59b). In the ''Apology'', Plato distances himself from the inner circle. Socrates says there that the brothers of several of his former associates are in the audience. He says that Adeimantus, brother to Plato, was present (''Apology'' 34a). Adeimantus appears in the ''Republic'' as a disputant.

Plato never presents himself as a participant in any of the dialogues, and with the exception of the ''Apology'', he does not claim to have heard any of the dialogues firsthand. Some dialogues have no narrator (examples: ''Meno'', ''Gorgias'', ''Phaedrus'', ''Crito'', ''Euthyphro''), some dialogues are narrated by Socrates, wherein he speaks in first person (examples: ''Lysis'', ''Charmides'', ''Apology'', ''Republic''). In one dialogue, ''Protagoras'', Socrates narrates to an unnamed friend a conversation he had previously with the sophist for whom the dialogue is named.

Three dialogues, ''Phaedo'', ''Symposium'', and ''Theaetetus'', are narrated by disciples of Socrates, and all, apparently, from distant memories. ''Phaedo'', an account of Socrates' final conversation and hemlock drinking, is narrated by Phaedo to Echecrates in a foreign city many years after the execution took place. The ''Symposium'' is narrated by Apollodorus, a Socratic disciple, apparently to Glaucon. Apollodorus assures his listener that he is recounting the story, which took place when he himself was an infant, not from his own memory, but as remembered by Aristodemus, who told him the story years ago. In the ''Theaetetus'' (142c-143b), Euclides says that he compiled the conversation from notes he took based on what Socrates told him of his conversation with the title character. With the exception of the ''Theaetetus'', Plato gives no hint as to how these orally transmitted conversations came to be written down, or how he came by them.

For some scholars, Plato's own absence from the dialogues, and the absence of a character who might readily be identified as holding Plato's actual view, is at odds with the traditional belief that he was a disciple and part of Socrates' inner circle. Nevertheless, the question of why Plato explicitly distances himself by time, place, and authorship from three of his greatest dialogues is in some respects no more an issue than other questions that the dialogues raise in terms of exegesis or interpretation. In this vein, it is worth noting that although tradition tends to see Plato as writing a kind of "pseudo-history" of the life of Socrates, the chronologies of the characters are inconsistent. For example, in the ''Protagoras'', Alcibiades and Agathon are teenage boys growing beards (and are the respective beloveds of Socrates and Pausanias), and Apollodoros and Glaucon are fathers of teenage sons. When the ''Symposium'' allegedly took place, however, Glaucon and Apollodorus were infants and Alcibiades and Agathon were full-grown men (and Alcibiades is said to be older than his beloved Agathon). This chronological discrepancy, which does not appear to be inadvertent, suggests that Plato is not a historical writer.

Plato's dialogues bear at least some similarities to the classical plays, in having no more than three speakers "on stage" (speaking) at one time, and in often having "a chorus" of (silent) listeners.

The trial of Socrates is the central, unifying event of the great Platonic dialogues. Because of this, Plato's ''Apology'' is perhaps the most often read of the dialogues. In the ''Apology'', Socrates tries to dismiss rumors that he is a sophist and defends himself against charges of disbelief in the gods and corruption of the young. Socrates insists that long-standing slander will be the real cause of his demise, and says the legal charges are essentially false. Socrates famously denies being wise, and explains how his life as a philosopher was launched by the oracle at Delphi. He says that his quest to resolve the riddle of the oracle put him at odds with his fellow man, and that this is the reason he has been mistaken for a menace to the city-state of Athens.

The trial of Socrates is anomalous: from what is known about Athens in the fifth century BC, it should not have taken place (see ''Gorgias'' 461e and ''Crito'' 45e). Atheism or similar charges was not unusual among intellectuals, nor condemned by the masses. The prize-winning plays of Aristophanes were not merely atheist, but made fun of the gods and their prophets and oracles. There is no record that Aristophanes was prosecuted for atheism, and some have speculated that comics enjoyed special immunities, though there is no evidence of this. It is also puzzling that Socrates exonerated himself in large part by claiming to be sent on his philosophic mission by Apollo, an important figure in the standard Greek pantheon.

If Plato's important dialogues do not refer to Socrates' execution explicitly, they allude to it, or use characters or themes that play a part in it. Five dialogues foreshadow the trial: In the ''Theaetetus'' (210d) and the ''Euthyphro'' (2a–b) Socrates tells people that he is about to face corruption charges. In the ''Meno'' (94e–95a), one of the men who brings legal charges against Socrates, Anytus, warns him about the trouble he may get into if he does not stop criticizing important people. In the ''Gorgias'', Socrates says that his trial will be like a doctor prosecuted by a cook who asks a jury of children to choose between the doctor's bitter medicine and the cook's tasty treats (521e–522a). In the ''Republic'' (7.517e), Socrates explains why an enlightened man (presumably himself) will stumble in a courtroom situation. The ''Apology'' is Socrates' defense speech, and the ''Crito'' and ''Phaedo'' take place in prison after the conviction. In the ''Protagoras'', Socrates is a guest at the home of Callias, son of Hipponicus, a man whom Socrates disparages in the ''Apology'' as having wasted a great amount of money on sophists' fees.

Two other important dialogues, the ''Symposium'' and the ''Phaedrus'', are linked to the main storyline by characters. In the ''Apology'' (19b, c), Socrates says Aristophanes slandered him in a comic play, and blames him for causing his bad reputation, and ultimately, his death. In the ''Symposium'', the two of them are drinking together with other friends. The character Phaedrus is linked to the main story line by character (Phaedrus is also a participant in the ''Symposium'' and the ''Protagoras'') and by theme (the philosopher as divine emissary, etc.) The ''Protagoras'' is also strongly linked to the ''Symposium'' by characters: all of the formal speakers at the ''Symposium'' (with the exception of Aristophanes) are present at the home of Callias in that dialogue. Charmides and his guardian Critias are present for the discussion in the ''Protagoras''. Examples of characters crossing between dialogues can be further multiplied. The ''Protagoras'' contains the largest gathering of Socratic associates.

In the dialogues for which Plato is most celebrated and admired, Socrates is concerned with human and political virtue, has a distinctive personality, and friends and enemies who "travel" with him from dialogue to dialogue. This is not to say that Socrates is consistent: a man who is his friend in one dialogue may be an adversary or subject of his mockery in another. For example, Socrates praises the wisdom of Euthyphro many times in the ''Cratylus'', but makes him look like a fool in the ''Euthyphro''. He disparages sophists generally, and Prodicus specifically in the ''Apology'', yet tells Theaetetus in his namesake dialogue that he admires Prodicus and has directed many pupils to him. In Cratylus (384b-c), Socrates says that he studied with Cratylus, and took his one-drachma course because he could not afford the full fifty-drachma course. Socrates' ideas are also not consistent within or between or among dialogues.

Some of Plato's dialogues are framed by human elements. The clearest example of this is ''Phaedo'', wherein Socrates dismisses his wife Xanthippe from the prison at the beginning of the dialogue, and again towards the end. The frame elements suggest that Socrates' relationship with his disciples, who mourn the imminent loss of their spiritual "father" is more important to him than his actual family. In this dialogue, an entire chorus of people is said to be silently listening to a very long conversation, and apparently, saying nothing.

Other dialogues, such as ''Euthyphro'' and ''Crito'', involve only two characters who are not said to be overheard by anyone else. The characters are meant to be compared and contrasted. Socrates is more like Euthyphro (whom he mocks) than he thinks. Both are pious men whose knowledge of god's will comes from different sources - Euthyphro reads myths and takes them literally, while Socrates relies on divine inspiration that originates in his soul. Socrates is less compatible with his friend Crito than he thinks, and even says that people who are so morally at odds ought to despise each other. Sometimes characters appear and disappear throughout the course of a dialogue without notice, as a slave and an aristocrat (Anytus) in the ''Meno''.

Two of Plato's dialogues are better described as monologues. They are called ''Apology'', and ''Menexenus''. ''Gorgias'', ''Protagoras'' and ''Lesser Hippias'' are structurally similar: each depicts Socrates being invited to converse with a well-known wise man who is visiting Athens. ''Lysis'' and ''Charmides'' are twin dialogues that picture Socrates chatting with boys who require attendants, slaves or older male relations who are appointed to walk them to and from their lessons at school. ''Phaedrus'' and the ''Symposium'' are a pair of dialogues linked by the theme of man-boy love.

Many other dialogues ascribed to Plato also use the Socratic character, but do not share this pronounced concern for virtue. In these dialogues, Plato uses Socrates as a mere name, a voice-marker who does not have the distinctive, self-deprecating wit of the important dialogues. The metaphysical dialogues attributed to Plato do not contain material of human interest, but are very abstract and read by specialists.

The dialogues have been divided by influential scholarship into the early, middle and late periods. The late Princeton scholar and classicist, Gregory Vlastos argued that the ''Euthyphro'', ''Apology'', ''Crito'' and ''Phaedo'' were written first and are a more or less historical record of the philosophy of the historical character Socrates. Vlastos' aim was to account for the obvious contradictions among dialogues. He argues that Plato's early dialogues represent Socratic philosophy, and that in the so-called middle and later dialogues, Plato expresses his own, quite different philosophy. Even Vlastos admitted that this division is not well-supported by the dialogues themselves. Nevertheless, his theory continues to be extremely influential.

The analogies in the dialogues are as interesting as the arguments, and just as important. Socrates' most enduring analogy is his comparison of the philosopher to the medical doctor. He says that the philosopher cures the mind ("psyche") of its worst affliction, ignorance, just as the medical doctor ("iatros") cures the body of disease. The ancient philosopher Epicurus took up the analogy, and claimed that any philosopher who did not reduce spiritual suffering was worthless. Socrates never pretended that his cures were pleasant, and never shied from saying that philosophical refutation, which chases false ideas from the brain, was a bitter medicine, and comparable to surgery or cautery. Diogenes of Sinope agreed. He reputedly said that a philosopher who did not hurt anybody's feeling was not doing his job. Even today, doctors of the mind are called "psych-iatrists".

Socrates compares the body to a prison house for the soul, and promoted the distinction that remains today, that a spiritual or wise person has a certain disgust for the body and its functions. In another celebrated analogy, Socrates likens the soul to a charioteer trying to manage a pair of lust ridden horses who ride by a love object, and start sweating and rearing uncontrollably. In still another comical analogy for the mind, Socrates says the brain is like a bird cage with pieces of knowledge fluttering about in it like doves and pigeons, so that a man might reach in for one fact and pull out the wrong one (''Theaetetus'').

Socrates frequently compares ideas with children, and says that ideas are the produce of the intercourse that men have with their beloved disciples (''Symp.'' 209a–e). In a related analogy, Socrates compares himself to a midwife to men and boys who are "pregnant with thought" (''Theaetetus''). In the Protagoras, Socrates compares ideas to food, claiming that sophists are more dangerous to the mind than peddlers of spoiled food are to the body.

In several dialogues, Socrates compares intellectual debate to the physical contests so popular in the ancient Greek world. In the ''Gorgias'' he says that trainers cannot be blamed for the misbehaviors of their students. He says that you would not exile his trainer if a boxing student started punching out his friends and parents, and just so, a teacher of rhetoric cannot be blamed if his students use their skills for unjust purposes. In the ''Lesser Hippias'', Socrates says that a person who lies deliberately is a better man than the man who lies unwittingly, just as a man who throws an athletic contest is better than the man who loses from lack of skill.

Much on Plato's mind is the father-son relationship, and the "question" of whether a father's interest in his sons has much to do with how well his sons turn out. A boy in ancient Athens was socially located by his family identity, and Plato often refers to his characters in terms of their paternal and fraternal relationships. Socrates was not a family man, and saw himself as the son of his mother, who was apparently a midwife. A divine fatalist, Socrates mocks men who spent exorbitant fees on tutors and trainers for their sons, and repeatedly ventures the idea that good character is a gift from the gods. Crito reminds Socrates that orphans are at the mercy of chance, but Socrates is unconcerned. In the ''Theaetetus'', he is found recruiting as a disciple a young man whose inheritance has been squandered. Socrates twice compares the relationship of the older man and his boy lover to the father-son relationship (''Lysis'' 213a, ''Republic'' 3.403b), and in the ''Phaedo'', Socrates' disciples, towards whom he displays more concern than his biological sons, say they will feel "fatherless" when he is gone. Many dialogues, like these, suggest that man-boy love (which is "spiritual") is a wise man's substitute for father-son biology (which is "bodily").

In several dialogues, Socrates floats the idea that Knowledge is a matter of recollection, and not of learning, observation, or study. He maintains this view somewhat at his own expense, because in many dialogues, Socrates complains of his forgetfulness. Socrates is often found arguing that knowledge is not empirical, and that it comes from divine insight. He is quite consistent in believing in the immortality of the soul, and several dialogues end with long speeches imagining the afterlife. More than one dialogue contrasts knowledge and opinion, perception and reality, nature and custom, and body and soul. The only contrast to this is his Parmenides.

Several dialogues tackle questions about art: Socrates says that poetry is inspired by the muses, and is not rational. He speaks approvingly of this, and other forms of divine madness (drunkeness, eroticism, and dreaming) in the ''Phaedrus ''(265a–c), and yet in the ''''Republic'''' wants to outlaw Homer's great poetry, and laughter as well. In ''Ion'', Socrates gives no hint of the disapproval of Homer that he expresses in the ''Republic''. The dialogue ''Ion'' suggests that Homer's ''Iliad'' functioned in the ancient Greek world as the bible does today in the modern Christian world: as divinely inspired literature that can provide moral guidance, if only it can be properly interpreted.

On politics and art, religion and science, justice and medicine, virtue and vice, crime and punishment, pleasure and pain, rhetoric and rhapsody, human nature and sexuality, love and wisdom, Socrates and his company of disputants had something to say.

"Platonism" is a term coined by scholars to refer to the intellectual consequences of denying, as Socrates often does, the reality of the material world. In several dialogues, most notably the Republic, Socrates inverts the common man's intuition about what is knowable and what is real. While most people take the objects of their senses to be real if anything is, Socrates is contemptuous of people who think that something has to be graspable in the hands to be real. In the ''Theaetetus'', he says such people are "eu a-mousoi", an expression that means literally, "happily without the muses" (''Theaetetus'' 156a). In other words, such people live without the divine inspiration that gives him, and people like him, access to higher insights about reality.

Socrates's idea that reality is unavailable to those who use their senses is what puts him at odds with the common man, and with common sense. Socrates says that he who sees with his eyes is blind, and this idea is most famously captured in his allegory of the cave, and more explicitly in his description of the divided line. The allegory of the cave (begins ''Republic'' 7.514a) is a paradoxical analogy wherein Socrates argues that the invisible world is the most intelligible ("noeton") and that the visible world ("(h)oraton") is the least knowable, and the most obscure. (This is exactly the opposite of what Socrates says to Euthyphro in the soothsayer's namesake dialogue. There, Socrates tells Euthyphro that people can agree on matters of logic and science, and are divided on moral matters, which are not so easily verifiable.)

Socrates says in the ''Republic'' that people who take the sun-lit world of the senses to be good and real are living pitifully in a den of evil and ignorance. Socrates admits that few climb out of the den, or cave of ignorance, and those who do, not only have a terrible struggle to attain the heights, but when they go back down for a visit or to help other people up, they find themselves objects of scorn and ridicule.

According to Socrates, physical objects and physical events are "shadows" of their ideal or perfect forms, and exist only to the extent that they instantiate the perfect versions of themselves. Just as shadows are temporary, inconsequential epiphenomena produced by physical objects, physical objects are themselves fleeting phenomena caused by more substantial causes, the ideals of which they are mere instances. For example, Socrates thinks that perfect justice exists (although it is not clear where) and his own trial would be a cheap copy of it.

The allegory of the cave (often said by scholars to represent Plato's own epistemology and metaphysics) is intimately connected to his political ideology (often said to also be Plato's own), that only people who have climbed out of the cave and cast their eyes on a vision of goodness are fit to rule. Socrates claims that the enlightened men of society must be forced from their divine contemplations and compelled to run the city according to their lofty insights. Thus is born the idea of the "philosopher-king", the wise person who accepts the power thrust upon him by the people who are wise enough to choose a good master. This is the main thesis of Socrates in the ''Republic'', that the most wisdom the masses can muster is the wise choice of a ruler.

The word metaphysics derives from the fact that Aristotle's musings about divine reality came after ("meta") his lecture notes on his treatise on nature ("physics"). The term is in fact applied to Aristotle's own teacher, and Plato's "metaphysics" is understood as Socrates' division of reality into the warring and irreconciliable domains of the material and the spiritual. The theory has been of incalculable influence in the history of Western philosophy and religion.

The Theory of Forms typically refers to Plato's belief that the material world as it seems to us is not the real world, but only a shadow of the real world. Plato spoke of forms in formulating his solution to the problem of universals. The forms, according to Plato, are roughly speaking archetypes or abstract representations of the many types and properties (that is, of universals) of things we see all around us.

Many have interpreted Plato as stating that knowledge is justified true belief, an influential view which informed future developments in modern analytic epistemology. This interpretation is based on a reading of the ''Theaetetus'' wherein Plato argues that belief is to be distinguished from knowledge on account of justification. Many years later, Edmund Gettier famously demonstrated the problems of the justified true belief account of knowledge. This interpretation, however, imports modern analytic and empiricist categories onto Plato himself and is better read on its own terms than as Plato's view.

Really, in the ''Sophist'', ''Statesman'', ''Republic'', and the ''Parmenides'' Plato himself associates knowledge with the apprehension of unchanging Forms and their relationships to one another (which he calls "expertise" in Dialectic). More explicitly, Plato himself argues in the ''Timaeus '' that knowledge is always proportionate to the realm from which it is gained. In other words, if one derives their account of something experientially, because the world of sense is in flux, the views therein attained will be mere opinions. And opinions are characterized by a lack of necessity and stability. On the other hand, if one derives their account of something by way of the non-sensible forms, because these forms are unchanging, so too is the account derived from them. It is only in this sense that Plato uses the term "knowledge."

In the Meno, Socrates uses a geometrical example to expound Plato's view that knowledge in this latter sense is acquired by recollection. Socrates elicits a fact concerning a geometrical construction from a slave boy, who could not have otherwise known the fact (due to the slave boy's lack of education). The knowledge must be present, Socrates concludes, in an eternal, non-experiential form.

Plato's philosophical views had many societal implications, especially on the idea of an ideal state or government. There is some discrepancy between his early and later views. Some of the most famous doctrines are contained in the ''Republic'' during his middle period, as well as in the ''Laws'' and the ''Statesman''. However, because Plato wrote dialogues, it is assumed that Socrates is often speaking for Plato. This assumption may not be true in all cases.

Plato, through the words of Socrates, asserts that societies have a tripartite class structure corresponding to the appetite/spirit/reason structure of the individual soul. The appetite/spirit/reason stand for different parts of the body. The body parts symbolize the castes of society.

* ''Productive'' Which represents the abdomen.(Workers) — the labourers, carpenters, plumbers, masons, merchants, farmers, ranchers, etc. These correspond to the "appetite" part of the soul. * ''Protective'' Which represents the chest.(Warriors or Guardians) — those who are adventurous, strong and brave; in the armed forces. These correspond to the "spirit" part of the soul. * ''Governing'' Which represents the head. (Rulers or Philosopher Kings) — those who are intelligent, rational, self-controlled, in love with wisdom, well suited to make decisions for the community. These correspond to the "reason" part of the soul and are very few.

According to this model, the principles of Athenian democracy (as it existed in his day) are rejected as only a few are fit to rule. Instead of rhetoric and persuasion, Plato says reason and wisdom should govern. As Plato puts it:

: "Until philosophers rule as kings or those who are now called kings and leading men genuinely and adequately philosophise, that is, until political power and philosophy entirely coincide, while the many natures who at present pursue either one exclusively are forcibly prevented from doing so, cities will have no rest from evils,... nor, I think, will the human race." (''Republic'' 473c-d)

Plato describes these "philosopher kings" as "those who love the sight of truth" (''Republic'' 475c) and supports the idea with the analogy of a captain and his ship or a doctor and his medicine. Sailing and health are not things that everyone is qualified to practice by nature. A large part of the ''Republic'' then addresses how the educational system should be set up to produce these philosopher kings.

However, it must be taken into account that the ideal city outlined in the ''Republic'' is qualified by Socrates as the ideal ''luxurious'' city, examined to determine how it is that injustice and justice grow in a city (''Republic'' 372e). According to Socrates, the "true" and "healthy" city is instead the one first outlined in book II of the ''Republic'', 369c–372d, containing farmers, craftsmen, merchants, and wage-earners, but lacking the guardian class of philosopher-kings as well as delicacies such as "perfumed oils, incense, prostitutes, and pastries", in addition to paintings, gold, ivory, couches, a multitude of occupations such as poets and hunters, and war.

In addition, the ideal city is used as an image to illuminate the state of one's soul, or the will, reason, and desires combined in the human body. Socrates is attempting to make an image of a rightly ordered human, and then later goes on to describe the different kinds of humans that can be observed, from tyrants to lovers of money in various kinds of cities. The ideal city is not promoted, but only used to magnify the different kinds of individual humans and the state of their soul. However, the philosopher king image was used by many after Plato to justify their personal political beliefs. The philosophic soul according to Socrates has reason, will, and desires united in virtuous harmony. A philosopher has the moderate love for wisdom and the courage to act according to wisdom. Wisdom is knowledge about the Good or the right relations between all that exists.

Wherein it concerns states and rulers, Plato has made interesting arguments. For instance he asks which is better - a bad democracy or a country reigned by a tyrant. He argues that it is better to be ruled by a bad tyrant (since then there is only one person committing bad deeds) than be a bad democracy (since here all the people are now responsible for such actions.)

According to Plato a state, which is made up of different kinds of souls, will overall decline from an aristocracy (rule by the best) to a timocracy (rule by the honorable), then to an oligarchy (rule by the few), then to a democracy (rule by the people), and finally to tyranny (rule by one person, rule by a tyrant). Perhaps Plato is trying to warn us of the various kinds of immoderate souls that can rule over a state, and what kind of wise souls are best to advise and give counsel to the rulers that are often lovers of power, money, fame, and popularity.

Plato's thought is often compared with that of his most famous student, Aristotle, whose reputation during the Western Middle Ages so completely eclipsed that of Plato that the Scholastic philosophers referred to Aristotle as "the Philosopher". However, in the Byzantine Empire, the study of Plato continued.

The Medieval scholastic philosophers did not have access to the works of Plato, nor the knowledge of Greek needed to read them. Plato's original writings were essentially lost to Western civilization until they were brought from Constantinople in the century before its fall, by George Gemistos Plethon. Medieval scholars knew of Plato only through translations into Latin from the translations into Arabic by Persian and Arab scholars. These scholars not only translated the texts of the ancients, but expanded them by writing extensive commentaries and interpretations on Plato's and Aristotle's works (see Al-Farabi, Avicenna, Averroes).

Only in the Renaissance, with the general resurgence of interest in classical civilization, did knowledge of Plato's philosophy become widespread again in the West. Many of the greatest early modern scientists and artists who broke with Scholasticism and fostered the flowering of the Renaissance, with the support of the Plato-inspired Lorenzo de Medici, saw Plato's philosophy as the basis for progress in the arts and sciences. By the 19th century, Plato's reputation was restored, and at least on par with Aristotle's.

Notable Western philosophers have continued to draw upon Plato's work since that time. Plato's influence has been especially strong in mathematics and the sciences. He helped to distinguish between pure and applied mathematics by widening the gap between "arithmetic", now called Number Theory and "logistic", now called arithmetic. He regarded logistic as appropriate for business men and men of war who "must learn the art of numbers or he will not know how to array his troops," while arithmetic was appropriate for philosophers "because he has to arise out of the sea of change and lay hold of true being." He further inspired some of the greatest advances in logic since Aristotle, due to Gottlob Frege and his followers Kurt Gödel, Alonzo Church, and Alfred Tarski, the last of whom summarised his approach by reversing Aristotle's famous declaration of sedition from the ''Nicomachean Ethics'' (1096a15: ''Amicus Plato sed magis amica veritas''): ''Inimicus Plato sed magis amica veritas'' ("Plato is a friend, but truth is yet a greater friend"). Albert Einstein drew on Plato's understanding of an immutable reality that underlies the flux of appearances for his objections to the probabilistic picture of the physical universe propounded by Niels Bohr in his interpretation of quantum mechanics. Conversely, thinkers that diverged from ontological models and moral ideals in their own philosophy, have tended to disparage Platonism from more or less informed perspectives. Thus Friedrich Nietzsche attacked Plato's moral and political theories, Martin Heidegger argued against Plato's alleged obfuscation of ''Being'', and Karl Popper argued in ''The Open Society and Its Enemies'' (1945) that Plato's alleged proposal for a government system in the ''Republic'' was prototypically totalitarian. Leo Strauss is considered by some as the prime thinker involved in the recovery of Platonic thought in its more political, and less metaphysical, form. Deeply influenced by Nietzsche and Heidegger, Strauss nonetheless rejects their condemnation of Plato and looks to the dialogues for a solution to what all three thinkers acknowledge as 'the crisis of the West.'

Plato's writings (most of them dialogues) have been published in several fashions; this has led to several conventions regarding the naming and referencing of Plato's texts.

Those works ascribed to Plato that have a separate Wikipedia article can be found in

One tradition regarding the arrangement of Plato's texts is according to tetralogies. This scheme is ascribed by Diogenes Laertius to an ancient scholar and court astrologer to Tiberius named Thrasyllus.

In the list below, works by Plato are marked (1) if there is no consensus among scholars as to whether Plato is the author, and (2) if scholars generally agree that Plato is ''not'' the author of the work. Unmarked works are assumed to have been written by Plato.

<div style="-moz-column-count:2; column-count:2;"> * I. ''Euthyphro'', ''(The) Apology (of Socrates)'', ''Crito'', ''Phaedo'' * II. ''Cratylus'', ''Theaetetus'', ''Sophist'', ''Statesman'' * III. ''Parmenides'', ''Philebus'', ''(The) Symposium'', ''Phaedrus'' * IV. ''First Alcibiades'' (1), ''Second Alcibiades'' (2), ''Hipparchus'' (2), ''(The) (Rival) Lovers'' (2) * V. ''Theages'' (2), ''Charmides'', ''Laches'', ''Lysis'' * VI. ''Euthydemus'', ''Protagoras'', ''Gorgias'', ''Meno'' * VII. ''(Greater) Hippias (major)'' (1), ''(Lesser) Hippias (minor)'', ''Ion'', ''Menexenus'' * VIII. ''Clitophon'' (1), ''(The) Republic'', ''Timaeus'', ''Critias'' * IX. ''Minos'' (2), ''(The) Laws'', ''Epinomis'' (2), ''Epistles'' (1). </div>

The remaining works were transmitted under Plato's name, most of them already considered spurious in antiquity, and so were not included by Thrasyllus in his tetralogical arrangement. These works are labelled as ''Notheuomenoi'' ("spurious") or ''Apocrypha''.

* ''Axiochus'' (2), ''Definitions'' (2), ''Demodocus'' (2), ''Epigrams'', ''Eryxias'' (2), ''Halcyon'' (2), ''On Justice'' (2), ''On Virtue'' (2), ''Sisyphus'' (2).

The usual system for making unique references to sections of the text by Plato derives from a 16th century edition of Plato's works by Henricus Stephanus. An overview of Plato's writings according to this system can be found in the Stephanus pagination article.

The exact order in which Plato's dialogues were written is not known, nor is the extent to which some might have been later revised and rewritten. However, according to modern linguistic theory there is enough information internal to the dialogues to form a rough chronology. The dialogues are normally grouped into three fairly distinct periods, with a few of them considered transitional works, and some just difficult to place. Friedrich Schleiermacher, whose translation of Plato into German still stands uncontested in Germany, is very likely the first to have divided Plato's dialogues into three distinct periods. However, his ordering is quite different from the modern one, and rather than being based upon philology, he claims to have traced Plato's philosophical development. Schleiermacher divides the dialogues thus:

# Foundation: ''Phaedrus'', ''Lysis'', ''Protagoras'', ''Laches'', ''Charmides'', ''Euthyphro'', ''Parmenides''; # Transition: ''Gorgias'', ''Theaetetus'', ''Meno'', ''Euthydemus'', ''Cratylus'', ''Sophist'', ''Statesman'', ''Symposium'', ''Phaedo'', ''Philebus'' # Culmination: ''The Republic'', ''(Critias, Timaeus, The Laws)''

The final three dialogues above, in parentheses, were not translated by Schleiermacher, though ten other dialogues (including ''Ion'', etc.) were translated and deemed spurious. Finally, Schleiermacher maintained that the ''Apology'' and probably the ''Crito'' were Plato's memory of Socrates' actual words.

Lewis Campbell was the first to make exhaustive use of stylometry to prove objectively that the ''Critias'', ''Timaeus'', ''Laws'', ''Philebus'', ''Sophist'', and ''Statesman'' were all clustered together as a group, while the ''Parmenides'', ''Phaedrus'', ''Republic'', and ''Theaetetus'' belong to a separate group, which must be earlier (given Aristotle's statement in his ''Politics'' that the ''Laws'' was written after the ''Republic''; cf. Diogenes Laertius ''Lives'' 3.37).

Many of the positions in the ordering are still highly disputed. The generally agreed upon modern ordering is as follows.

Socrates figures in all of these, and they are considered the most faithful representations of the historical Socrates; hence they are also called the Socratic dialogues. Most of them consist of Socrates discussing a subject, often an ethical one (friendship, piety) with a friend or with someone presumed to be an expert on it. Through a series of questions he will show that apparently they do not understand it at all. It is left to the reader to figure out if "he" really understands "it". This makes these dialogues "indirect" teachings. This period also includes several pieces surrounding the trial and execution of Socrates.

* ''Apology'' * ''Crito'' * ''Charmides'' * ''Laches'' * ''Lysis'' * ''Euthyphro'' * ''Menexenus'' * ''Lesser Hippias'' * ''Ion''

The following are variously considered transitional or middle period dialogues:

* ''Gorgias'' * ''Protagoras'' * ''Meno''

Late in the early dialogues Plato's Socrates actually begins supplying answers to some of the questions he asks, or putting forth positive doctrines. This is generally seen as the first appearance of Plato's own views. The first of these, that goodness is wisdom and that no one does evil willingly, was perhaps Socrates' own view. What becomes most prominent in the middle dialogues is the idea that knowledge comes of grasping unchanging forms or essences, paired with the attempts to investigate such essences. The immortality of the soul, and specific doctrines about justice, truth, and beauty, begin appearing here. The Symposium and the Republic are considered the centrepieces of Plato's middle period.

* ''Euthydemus'' * ''Cratylus'' * ''Phaedo'' * ''Phaedrus'' * ''Symposium'' * ''Republic'' * ''Theaetetus'' * ''Parmenides''

The ''Parmenides'' presents a series of criticisms of the theory of Forms which are widely taken to indicate Plato's abandonment of the doctrine. Some recent publications (e.g., Meinwald (1991)) have challenged this characterisation. In most of the remaining dialogues the theory is either absent or at least appears under a different guise in discussions about kinds or classes of things (the ''Timaeus'' may be an important, and hence controversially placed, exception). Socrates is either absent or a minor figure in the discussion. An apparently new method for doing dialectic known as "collection and division" is also featured, most notably in the ''Sophist'' and ''Statesman'', explicitly for the first time in the ''Phaedrus'', and possibly in the ''Philebus''. A basic description of collection and division would go as follows: interlocutors attempt to discern the similarities and differences among things in order to get clear idea about what they in fact are. One understanding, suggested in some passages of the ''Sophist'', is that this is what philosophy is always in the business of doing, and is doing even in the early dialogues.

The late dialogues are also an important place to look for Plato's mature thought on most of the issues dealt with in the earlier dialogues. There is much work still to be done by scholars on the working out of what these views are. The later works are agreed to be difficult and challenging pieces of philosophy. On the whole they are more sober and logical than earlier works, but may hold out the promise of steps towards a solution to problems which were systematically laid out in prior works.

* ''Sophist'' * ''Statesman'' * ''Philebus'' * ''Timaeus'' * ''Critias'' * ''Laws''

James Loeb provided a very popular edition of Plato's works, still in print in the 21st century: see Loeb Classical Library#Plato for how Plato's works were named in Loeb's publications.

* Platonic Realism * Mitchell Miller * Eric A. Havelock * Alexander Nehamas * Platonic love * Seventh Letter (Plato) * Cambridge Platonists * Jacob Klein (philosopher)

<div class="references-small"> </b>a. The grammarian Apollodorus argues in his ''Chronicles'' that Plato was born in the first year of the eighty-eighth Olympiad (427 BC), on the seventh day of the month Thargelion; according to this tradition the god Apollo was born this day. According to another biographer of him, Neanthes, Plato was eighty-four years of age at his death. If we accept Neanthes' version, Plato was younger than Isocrates by six years, and therefore he was born in the second year of the 87th Olympiad, the year Pericles died (429 BC). According to the ''Suda,'' Plato was born in Aegina in the 88th Olympiad amid the preliminaries of the Peloponnesian war, and he lived 82 years. Sir Thomas Browne also believes that Plato was born in the 88th Olympiad. Renaissance Platonists celebrated Plato's birth on November 7. Wilamowitz-Moellendorff estimates that Plato was born when Diotimos was archon eponymous, namely between July 29428 BC and July 24427 BC. Greek philologist Ioannis Kalitsounakis believes that the philosopher was born on May 26 or 27 427 BC, while Jonathan Barnes regards 428 BC as year of Plato's birth. For her part, Debra Nails asserts that the philosopher was born in 424/423 BC.

b. Diogenes Laertius mentions that Plato "was born, according to some writers, in Aegina in the house of Phidiades the son of Thales". Diogenes mentions as one of his sources the ''Universal History'' of Favorinus. According to Favorinus, Ariston, Plato's family, and his family were sent by Athens to settle as cleruchs (colonists retaining their Athenian citizenship), on the island of Aegina, from which they were expelled by the Spartans after Plato's birth there. Nails points out, however, that there is no record of any Spartan expulsion of Athenians from Aegina between 431-411 BC. On the other hand, at the Peace of Nicias, Aegina was silently left under Athens' control, and it was not until the summer of 411 that the Spartans overran the island. Therefore, Nails concludes that "perhaps Ariston was a cleruch, perhaps he want to Aegina in 431, and perhaps Plato was born on Aegina, but none of this enables a precise dating of Ariston's death (or Plato's birth). Aegina is regarded as Plato's place of birth by Suda as well.

c.''' Plato was a common name, of which 31 instances are known at Athens alone.

</div>

<div class="references-small"> *Apuleius, De Dogmate Platonis, I. See original text in Latin Library. *Aristophanes, The Wasps. See original text in Perseus program. *Aristotle, Metaphysics. See original text in Perseus program. *Cicero, De Divinatione, I. See original text in Latin library. *Diogenes Laertius, Life of Plato. Translated by C.D. Yonge. *. See original text in Perseus program. *. See original text in Perseus program. *Plato, Parmenides. See original text in Perseus program. *. See original text in Perseus program. * Plutarch, Pericles. See original text in Perseus program. *, V, VIII. See original text in Perseus program. *Xenophon, Memorabilia. See original text in Perseus program<i>. </div>

<div class="references-small"> * * * * * * * * * * * * * * </div>

* Allen, R.E. (2006). </i>Studies in Plato's Metaphysics II. Parmenides Publishing. ISBN 978-1-930972-18-6 * Ambuel, David (2006). Image and Paradigm in Plato's Sophist. Parmenides Publishing. ISBN 978-1-930972-004-9 *Bakalis, Nikolaos (2005). Handbook of Greek Philosophy: From Thales to the Stoics Analysis and Fragments, Trafford Publishing ISBN 1-4120-4843-5 * * * Corlett, J. Angelo (2005). Interpreting Plato's Dialogues. Parmenides Publishing. ISBN 978-1-930972-02-5 * * Derrida, Jacques (1972). La dissémination, Paris: Seuil. (esp. cap.: La Pharmacie de Platon, 69-199) ISBN 2-02-001958-2 * Fine, Gail (2000). Plato 1: Metaphysics and Epistemology Oxford University Press, USA, ISBN 0-19-875206-7 * Guthrie, W. K. C. (1986). A History of Greek Philosophy (Plato - The Man & His Dialogues - Earlier Period), Cambridge University Press, ISBN 0-521-31101-2 * Guthrie, W. K. C. (1986). A History of Greek Philosophy (Later Plato & the Academy) Cambridge University Press, ISBN 0-521-31102-0 *Havelock, Eric (2005). çPreface to Plato (History of the Greek Mind), Belknap Press, ISBN 0-674-69906-8 * *Irwin, Terence (1995). Plato's Ethics, Oxford University Press, USA, ISBN 0-19-508645-7 * * * * Lilar, Suzanne (1954), Journal de l'analogiste, Paris, Éditions Julliard; Reedited 1979, Paris, Grasset. Foreword by Julien Gracq * Lilar, Suzanne (1963), "Le couple", Paris, Grasset. Translated as "Aspects of Love in Western Society" in 1965, with a foreword by Jonathan Griffin London, Thames and Hudson. * Lilar, Suzanne (1967) A propos de Sartre et de l'amour , Paris, Grasset. * * * * Miller, Mitchell (2004). The Philosopher in Plato's Statesman. Parmenides Publishing. ISBN 978-1-930972-16-2 * Mohr, Richard D. (2006). God and Forms in Plato - and other Essays in Plato's Metaphysics. Parmenides Publishing. ISBN 978-1-930972-01-6 * Moore, Edward (2007). Plato. Philosophy Insights Series. Tirril, Humanities-Ebooks. ISBN 978-1-84760-047-9 * * * Sayre, Kenneth M. (2006). Plato's Late Ontology: A Riddle Resolved. Parmenides Publishing. ISBN 978-1-930972-09-4 * Taylor, A. E. (2001). Plato: The Man and His Work, Dover Publications, ISBN 0-486-41605-4 * Vlastos, Gregory (1981). Platonic Studies, Princeton University Press, ISBN 0-691-10021-7 * Vlastos, Gregory (2006). Plato's Universe - with a new Introducution by Luc Brisson, Parmenides Publishing. ISBN 978-1-930972-13-1 * Oxford University Press publishes scholarly editions of Plato's Greek texts in the Oxford Classical Texts series, and some translations in the Clarendon Plato Series. * Harvard University Press publishes the hardbound series Loeb Classical Library, containing Plato's works in Greek, with English translations on facing pages. * *Aspects of antiquity: Discoveries and Controversies by M.I. Finley, issued 1969 by The Viking Press, Inc. *Interpreting Plato: The Dialogues as Drama by James A. Arieti, Rowman & Littlefield Publishers, Inc. ISBN 0-8476-7662-5

*Works available on-line ** - Greek & English hyperlinked text ** Works of Plato (Jowett, 1892) ** *** Spurious and doubtful works at Project Gutenberg ** Plato complete works, annotated and searchable, at ELPENOR ** Euthyphro LibriVox recording ** Ion LibriVox recording

* Stanford Encyclopedia of Philosophy: ** Plato ** Plato's Ethics ** Friendship and Eros ** Middle Period Metaphysics and Epistemology ** Plato on Utopia ** Rhetoric and Poetry

* Other Articles: ** Excerpt from W.K.C. Guthrie, A History of Greek Philosophy, vol. IV, Plato: the man and his dialogues, earlier period, Cambridge University Press, 1989, pp. 8-38 ** Website on Plato and his works: Plato and his dialogues by Bernard Suzanne ** Are there really Platonic forms? ** "Plato and Totalitarianism: A Documentary Study" ** The New Academy

* Plato Bibliography at PlatoGeek * Online library "Vox Philosophiae"

* Plato Plato * Plato