Plato is one of the world's best known and most widely read and studied philosophers. Known as the student of Socrates and the teacher of Aristotle, he wrote in the middle of the fourth century B.C.E. His earliest works are regarded as the most reliable of the ancient sources on Socrates. His later works, including his most famous work, the Republic, blend ethics, political philosophy, moral psychology, epistemology, and metaphysics into an interconnected and systematic philosophy. It is most of all from Plato that we get the theory of Forms, according to which the world we know through the senses is only an imitation of the pure, eternal, and unchanging world of the Forms. Plato's works also contain the origins of the familiar complaint that the arts work by inflaming the passions, the ideal of "Platonic love," and the myth of Atlantis.

Birth

It is widely accepted that Plato, the Athenian philosopher, was born in 428-7 B.C.E and died at the age of eighty or eighty-one at 348-7 B.C.E. These dates, however, are not entirely certain, for according to Diogenes Laertius, following Apollodorus' chronology, Plato was born the year Pericles died, was six years younger than Isocrates, and died at the age of eighty-four ( D.L. 3.2-3.3). If Plato's date of death is correct in Apollodorus' version, Plato would have been born in 430 or 431. Diogenes' claim that Plato was born the year Pericles died would put his birth in 429. Later (at 3.6), Diogenes says that Plato was twenty-eight when Socrates was put to death (in 399), which would, again, put his year of birth at 427. In spite of the confusion, the dates of Plato's life we gave above, which are based upon Eratosthenes' calculations, have traditionally been accepted as accurate.

Family

Little can be known about Plato's early life. According to Diogenes, whose testimony is notoriously unreliable, Plato's parents were Ariston and Perictione (or Potone--see D. L. 3.1). Both sides of the family claimed to trace their ancestry back to Poseidon ( D.L. 3.1). Diogenes' report that Plato's birth was the result of Ariston's rape of Perictione ( D.L. 3.1) is a good example of the unconfirmed gossip in which Diogenes so often indulges. We can be confident that Plato also had two older brothers, Glaucon and Adeimantus, and a sister, Potone, by the same parents (see D.L. 3.4). (W. K. C. Guthrie, A History of Greek Philosophy, vol. 4, 10 n. 4 argues plausibly that Glaucon and Adeimantus were Plato's older siblings.) After Ariston's death, Plato's mother married her uncle, Pyrilampes (in Plato's Charmides, we are told that Pyrilampes was Charmides' uncle, and Charmides was Plato's mother's brother), with whom she had another son, Antiphon, Plato's half-brother (see Plato, Parmenides 126a-b).

Plato came from one of the wealthiest and most politically active families in Athens. Their political activities, however, are not seen as laudable ones by historians. One of Plato's uncles (Charmides) was a member of the notorious "Thirty Tyrants," who overthrew the Athenian democracy in 404 B.C.E. Charmides' own uncle, Critias, was the leader of the Thirty. Plato's relatives were not exclusively associated with the oligarchic faction in Athens, however. His stepfather Pyrilampes was said to have been a close associate of Pericles, when he was the leader of the democratic faction.

Plato's actual given name was apparently Aristocles, after his grandfather. "Plato" seems to have started as a nickname (for platos, or "broad"), perhaps first given to him by his wrestling teacher for his physique, or for the breadth of his style, or even the breadth of his forehead (all given in D.L. 3.4). Although the name Aristocles was still given as Plato's name on one of the two epitaphs on his tomb (see D.L. 3.43), history knows him as Plato.

Early Travels and the Founding of the Academy

When Socrates died, Plato left Athens, staying first in Megara, but then going on to several other places, including perhaps Cyrene, Italy, Sicily, and even Egypt. Strabo (17.29) claims that he was shown where Plato lived when he visited Heliopolis in Egypt. Plato occasionally mentions Egypt in his works, but not in ways that reveal much of any consequence (see, for examples, Phaedrus 274c-275b; Philebus 19b).

Better evidence may be found for his visits to Italy and Sicily, especially in the Seventh Letter. According to the account given there, Plato first went to Italy and Sicily when he was "about forty" (324a). While he stayed in Syracuse, he became the instructor to Dion, brother-in-law of the tyrant Dionysius I. According to doubtful stories from later antiquity, Dionysius became annoyed with Plato at some point during this visit, and arranged to have the philosopher sold into slavery (Diod. 15.7; Plut. Dion 5; D.L. 3.19-21).

In any event, Plato returned to Athens and founded a school, known as the Academy (from which we get our word, "academic," but which got its name from its location, a grove of trees sacred to the hero Academus-or Hecademus [see D.L. 3.7]-a mile or so outside the Athenian walls; the site can still be visited in modern Athens, but visitors will find it depressingly void of interesting monuments or features). Except for two more trips to Sicily, the Academy seems to have been Plato's home base for the remainder of his life.

Later Trips to Sicily and Death

The first of Plato's remaining two Sicilian adventures came after Dionysius I died and his young son, Dionysius II, ascended to the throne. His uncle/brother-in-law Dion persuaded the young tyrant to invite Plato to come to help him become a philosopher-ruler of the sort described in the Republic. Although the philosopher (now in his sixties) was not entirely persuaded of this possibility ( Seventh Letter 328b-c), he agreed to go. This trip, like the last one, however, did not go well at all. Within months, the younger Dionysius had Dion sent into exile for sedition ( Seventh Letter 329c, Third Letter 316c-d), and Plato became effectively under house arrest as the "personal guest" of the dictator ( Seventh Letter 329c-330b).

Plato eventually managed to gain the tyrant's permission to return to Athens ( Seventh Letter 338a), and he and Dion were reunited at the Academy (Plut. Dion 17). Dionysius agreed that "after the war" ( Seventh Letter 338a; perhaps the Lucanian War in 365 B.C.E.), he would invite Plato and Dion back to Syracuse ( Third Letter 316e-317a, Seventh Letter 338a-b). Dion and Plato stayed in Athens for the next four years (c. 365-361 B.C.E.). Dionysius then summoned Plato, but wished for Dion to wait a while longer. Dion accepted the condition and encouraged Plato to go immediately anyway ( Third Letter 317a-b, Seventh Letter 338b-c), but Plato refused the invitation, much to the consternation of both Syracusans ( Third Letter 317a, Seventh Letter 338c). Hardly a year had passed, however, before Dionysius sent a ship, with one of Plato's Pythagorean friends (Archedemus, an associate of Archytas-see Seventh Letter 339a-b and next section) on board begging Plato to return to Syracuse. Partly because of his friend Dion's enthusiasm for the plan, Plato departed one more time to Syracuse. Once again, however, things in Syracuse were not at all to Plato's liking. Dionysius once again effectively imprisoned Plato in Syracuse, and the latter was only able to escape again with help from his Tarentine friends ( Seventh Letter 350a-b).

Dion subsequently gathered an army of mercenaries and invaded his own homeland. But his success was short-lived: He was assassinated and Sicily was reduced to chaos. Plato-perhaps now completely disgusted with politics-returned to his beloved Academy, where he lived out the last thirteen years of his life. According to Diogenes, Plato was buried at the school he founded ( D.L. 3.41). His grave, however, has not yet been discovered by archeological investigations.

Influences on Plato

Heraclitus

Aristotle and Diogenes agree that Plato had some early association with either the philosophy of Heraclitus of Ephesus, or with one or more of that philosopher's followers (see Aristotle Metaph. 987a32, D.L. 3.4-3.5). The effects of this influence can perhaps be seen in the mature Plato's conception of the sensible world as ceaselessly changing.

Parmenides and Zeno

There can be no doubt that Plato was also strongly influenced by Parmenides and Zeno (both of Elea), in Plato's theory of the Forms, which are plainly intended to satisfy the Parmenidean requirement of metaphysical unity and stability in knowable reality. Parmenides and Zeno also appear as characters in his dialogue, the Parmenides. Diogenes Laertius also notes other important influences:

He mixed together in his works the arguments of Heracleitus, the Pythagoreans, and Socrates. Regarding the sensibles, he borrows from Heraclitus; regarding the intelligibles, from Pythagoras; and regarding politics, from Socrates. ( D.L. 3.8)

The Pythagoreans

Diogenes Laertius (3.6) claims that Plato visited several Pythagoreans in Southern Italy (one of whom, Theodorus, is also mentioned as a friend to Socrates in Plato's Theaetetus). In the Seventh Letter, we learn that Plato was a friend of Archytas of Tarentum, a well-known Pythagorean statesman and thinker (see 339d-e), and in the Phaedo, Plato has Echecrates, another Pythagorean, in the group around Socrates on his final day in prison. Plato's Pythagorean influences seem especially evident in his fascination with mathematics, and in some of his political ideals, expressed in various ways in several dialogues.

Socrates

Nonetheless, it is plain that no influence on Plato was greater than that of Socrates. This is evident not only in many of the doctrines and arguments we find in Plato's dialogues, but perhaps most obviously in Plato's choice of Socrates as the main character in most of his works. According to the Seventh Letter, Plato counted Socrates "the justest man alive" (324e). According to Diogenes Laertius, the respect was mutual (3.5).

Plato's Writings

Plato's Dialogues and the Historical Socrates

Supposedly possessed of outstanding intellectual and artistic ability even from his youth, according to Diogenes, Plato began his career as a writer of tragedies, but hearing Socrates talk, he wholly abandoned that path, and even burned a tragedy he had hoped to enter in a dramatic competition ( D.L. 3.5). Whether or not any of these stories is true, there can be no question of Plato's mastery of dialogue, characterization, and dramatic context. He may, indeed, have written some epigrams; of the surviving epigrams attributed to him in antiquity, some may be genuine.

Plato was not the only writer of dialogues in which Socrates appears as a principal character and speaker. Others, including Alexamenos of Teos (Aristotle Poetics 1447b11; De Poetis fr. 3 Ross [=Rose² 72]), Aeschines (D.L. 2.60-63, 3.36, Plato Apology 33e), Antisthenes ( D.L. 3.35, 6; Plato, Phaedo 59b; Xenophon, Memorabilia 2.4.5, 3.2.17), Aristippus ( D.L. 2.65-104, 3.36, Plato Phaedo 59c), Eucleides ( D.L. 2.106-112), Phaedo ( D.L. 2.105; Plato, Phaedo passim), Simon ( D.L. 122-124), and especially Xenophon (see D.L. 2.48-59, 3.34), were also well-known "Socratics" who composed such works. A recent study of these, by Charles H. Kahn (1996, 1-35), concludes that the very existence of the genre-and all of the conflicting images of Socrates we find given by the various authors-shows that we cannot trust as historically reliable any of the accounts of Socrates given in antiquity, including those given by Plato.

But it is one thing to claim that Plato was not the only one to write Socratic dialogues, and quite another to hold that Plato was only following the rules of some genre of writings in his own work. Such a claim, at any rate, is hardly established simply by the existence of these other writers and their writings. We may still wish to ask whether Plato's own use of Socrates as his main character has anything at all to do with the historical Socrates. The question has led to a number of seemingly irresolvable scholarly disputes. At least one important ancient source, Aristotle, suggests that at least some of the doctrines Plato puts into the mouth of the "Socrates" of the "early" or "Socrates" dialogues are the very ones espoused by the historical Socrates. Because Aristotle has no reason not to be truthful about this issue, many scholars believe that his testimony provides a solid basis for distinguishing the "Socrates" of the "early" dialogues from the character by that name in Plato's supposedly later works, whose views and arguments Aristotle suggests are Plato's own.

Dating Plato's Dialogues

One way to approach this issue has been to find some way to arrange the dialogues into at least relative dates. It has frequently been assumed that if we can establish a relative chronology for when Plato wrote each of the dialogues, we can provide some objective test for the claim that Plato represented Socrates more accurately in the earlier dialogues, and less accurately in the later dialogues.

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Transmission of Plato's Works

Except for the Timaeus, all of Plato's works were lost to the Western world until medieval times, preserved only by Moslem scholars in the Middle East. In 1578 Henri Estienne (whose Latinized name was Stephanus) published an edition of the dialogues in which each page of the text is separated into five sections (labeled a, b, c, d, and e). The standard style of citation for Platonic texts includes the name of the text, followed by Stephanus page and section numbers (e.g. Republic 511d). Scholars sometimes also add numbers after the Stephanus section letters, which refer to line numbers within the Stephanus sections in the standard Greek edition of the dialogues, the Oxford Classical texts.

The Early Dialogues

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Plato's Characterization of Socrates

In the dialogues generally accepted as early (or "Socratic"), the main character is always Socrates. Socrates is represented as extremely agile in question-and-answer, which has come to be known as "the Socratic method of teaching," or "the elenchus" (or elenchos-from the Greek term for refutation), with Socrates nearly always playing the role as questioner, for he claimed to have no wisdom of his own to share with others. Plato's Socrates, in this period, was adept at reducing even the most difficult and recalcitrant interlocutors to confusion and self-contradiction. In the Apology, Socrates explains that the embarrassment he has thus caused to so many of his contemporaries is the result of a Delphic oracle given to Socrates' friend Chaerephon (Apology 21a-23b), according to which no one was wiser than Socrates. As a result of his attempt to discern the true meaning of this oracle, Socrates gained a divinely ordained mission in Athens to expose the false conceit of wisdom. The embarrassment his "investigations" have caused to so many of his contemporaries-which Socrates claims was the root cause of his being brought up on charges (Apology 23c-24b)-is thus no one's fault but his "victims'," for having chosen to live "the unexamined life" (see 38a).

The way that Plato's represents Socrates going about his "mission" in Athens provides a plausible explanation both of why the Athenians would have brought him to trial and convicted him in the troubled years after the end of the Peloponnesian War, and also of why Socrates was not really guilty of the charges he faced. Even more importantly, however, Plato's early dialogues provide intriguing arguments and refutations of proposed philosophical positions that interest and challenge philosophical readers. Platonic dialogues continue to be included among the required readings in introductory and advanced philosophy classes, not only for their ready accessibility, but also because they raise many of the most basic problems of philosophy. Unlike most other philosophical works, moreover, Plato frames the discussions he represents in dramatic settings that make the content of these discussions especially compelling. So, for example, in the Crito, we find Socrates discussing the citizen's duty to obey the laws of the state as he awaits his own legally mandated execution in jail, condemned by what he and Crito both agree was a terribly wrong verdict, the result of the most egregious misapplication of the very laws they are discussing. The dramatic features of Plato's works have earned attention even from literary scholars relatively uninterested in philosophy as such. Whatever their value for specifically historical research, therefore, Plato's dialogues will continue to be read and debated by students and scholars, and the Socrates we find in the early or "Socratic" dialogues will continue to be counted among the greatest Western philosophers.

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The Middle Dialogues

Differences between the Early and Middle Dialogues

Scholarly attempts to provide relative chronological orderings of the early transitional and middle dialogues are problematical because all agree that the main dialogue of the middle period, the Republic, has several features that make dating it precisely especially difficult. As we have already said, many scholars count the first book of the Republic as among the early group of dialogues. But those who read the entire Republic will also see that the first book also provides a natural and effective introduction to the remaining books of the work. A recent study by Debra Nails ("The Dramatic Date of Plato's Republic," The Classical Journal 93.4, 1998, 383-396) notes several anachronisms that suggest that the process of writing (and perhaps re-editing) the work may have continued over a very long period. If this central work of the period is difficult to place into a specific context, there can be no great assurance in positioning any other works relative to this one.

Nonetheless, it does not take especially careful study of the transitional and middle period dialogues to notice clear differences in style and philosophical content from the early dialogues. The most obvious change is the way in which Plato seems to characterize Socrates: In the early dialogues, we find Socrates simply asking questions, exposing his interlocutors' confusions, all the while professing his own inability to shed any positive light on the subject, whereas in the middle period dialogues, Socrates suddenly emerges as a kind of positive expert, willing to affirm and defend his own theories about many important subjects. In the early dialogues, moreover, Socrates discusses mainly ethical subjects with his interlocutors-with some related religious, methodological, and epistemological views scattered within the primarily ethical discussions. In the middle period, Plato's Socrates' interests expand outward into nearly every area of inquiry known to humankind. The philosophical positions Socrates advances in these dialogues are vastly more systematical, including broad theoretical inquiries into the connections between language and reality (in the Cratylus), knowledge and explanation (in the Phaedo and Republic, Books V-VII). Unlike the Socrates of the early period, who was the "wisest of men" only because he recognized the full extent of his own ignorance, the Socrates of the middle period acknowledges the possibility of infallible human knowledge (especially in the famous similes of light, the simile of the sun and good and the simile of the divided line in Book VI and the parable of the cave in Book VII of the Republic), and this becomes possible in virtue of a special sort of cognitive contact with the Forms or Ideas (eidê ), which exist in a supra-sensible realm available only to thought. This theory of Forms, introduced and explained in various contexts in each of the middle period dialogues, is perhaps the single best-known and most definitive aspect of what has come to be known as Platonism.

The Theory of Forms

In many of his dialogues, Plato mentions supra-sensible entities he calls "Forms" (or "Ideas"). So, for example, in the Phaedo, we are told that particular sensible equal things-for example, equal sticks or stones (see Phaedo 74a-75d)-are equal because of their "participation" or "sharing" in the character of the Form of Equality, which is absolutely, changelessly, perfectly, and essentially equal. Plato sometimes characterizes this participation in the Form as a kind of imaging, or approximation of the Form. The same may be said of the many things that are greater or smaller and the Forms of Great and Small (Phaedo 75c-d), or the many tall things and the Form of Tall (Phaedo 100e), or the many beautiful things and the Form of Beauty (Phaedo 75c-d, Symposium 211e, Republic V.476c). When Plato writes about instances of Forms "approximating" Forms, it is easy to infer that, for Plato, Forms are exemplars. If so, Plato believes that The Form of Beauty is perfect beauty, the Form of Justice is perfect justice, and so forth. Conceiving of Forms in this way was important to Plato because it enabled the philosopher who grasps the entities to be best able to judge to what extent sensible instances of the Forms are good examples of the Forms they approximate.

Scholars disagree about the scope of what is often called "the theory of Forms," and question whether Plato began holding that there are only Forms for a small range of properties, such as tallness, equality, justice, beauty, and so on, and then widened the scope to include Forms corresponding to every term that can be applied to a multiplicity of instances. In the Republic, he writes as if there may be a great multiplicity of Forms-for example, in Book X of that work, we find him writing about the Form of Bed (see Republic X.596b). He may have come to believe that for any set of things that shares some property, there is a Form that gives unity to the set of things (and univocity to the term by which we refer to members of that set of things). Knowledge involves the recognition of the Forms (Republic V.475e-480a), and any reliable application of this knowledge will involve the ability compare the particular sensible instantiations of a property to the Form.

Immortality and Reincarnation

In the early transitional dialogue, the Meno, Plato has Socrates introduce the Orphic and Pythagorean idea that souls are immortal and existed before our births. All knowledge, he explains, is actually recollected from this prior existence. In perhaps the most famous passage in this dialogue, Socrates elicits recollection about geometry from one of Meno's slaves (Meno 81a-86b). Socrates' apparent interest in, and fairly sophisticated knowledge of, mathematics appears wholly new in this dialogue. It is an interest, however, that shows up plainly in the middle period dialogues, especially in the middle books of the Republic.

Several arguments for the immortality of the soul, and the idea that souls are reincarnated into different life forms, are also featured in Plato's Phaedo (which also includes the famous scene in which Socrates drinks the hemlock and utters his last words). Stylometry has tended to count the Phaedo among the early dialogues, whereas analysis of philosophical content has tended to place it at the beginning of the middle period. Similar accounts of the transmigration of souls may be found, with somewhat different details, in Book X of the Republic and in the Phaedrus, as well as in several dialogues of the late period, including the Timaeus and the Laws. No traces of the doctrine of recollection, or the theory of reincarnation or transmigration of souls, are to be found in the dialogues we listed above as those of the early period.

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Platonic Love

In the Symposium, which is normally dated at the beginning of the middle period, and in the Phaedrus, which is dated at the end of the middle period or later yet, Plato introduces his theory of erôs (usually translated as "love"). Several passages and images from these dialogues continued to show up in Western culture-for example, the image of two lovers as being each other's "other half," which Plato assigns to Aristophanes in the Symposium. Also in that dialogue, we are told of the "ladder of love," by which the lover can ascend to direct cognitive contact with (usually compared to a kind of vision of) Beauty Itself. In the Phaedrus, love is revealed to be the great "divine madness" through which the wings of the lover's soul may sprout, allowing the lover to take flight to all of the highest aspirations and achievements possible for humankind. In both of these dialogues, Plato clearly regards actual physical or sexual contact between lovers as degraded and wasteful forms of erotic expression. Because the true goal of erôs is real beauty and real beauty is the Form of Beauty, what Plato calls Beauty Itself, erôs finds its fulfillment only in Platonic philosophy. Unless it channels its power of love into "higher pursuits," which culminate in the knowledge of the Form of Beauty, erôs is doomed to frustration. For this reason, Plato thinks that most people sadly squander the real power of love by limiting themselves to the mere pleasures of physical beauty.

Late Transitional and Late Dialogues

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The "Eclipse" of Socrates

In several of the late dialogues, Socrates is even further marginalized-either represented as a mostly mute bystander (in the Sophist and Statesman), or else absent altogether from the cast of characters (in the Laws and Critias). In the Theaetetus and Philebus, however, we find Socrates in the familiar leading role. The so-called "eclipse" of Socrates in several of the later dialogues has been a subject of much scholarly discussion.

The Myth of Atlantis

Plato's famous myth of Atlantis is first given in the Timaeus, which scholars now generally agree is quite late, despite being dramatically placed on the day after the discussion recounted in the Republic. The myth of Atlantis is continued in the unfinished dialogue intended to be the sequel to the Timaeus, the Critias.

The Creation of the Universe

The Timaeus is also famous for its account of the creation of the universe by the Demiurge. Unlike the creation by the God of medieval theologians, Plato's Demiurge does not create ex nihilo, but rather orders the cosmos out of chaotic elemental matter, imitating the eternal Forms. Plato takes the four elements, fire, air, water, and earth (which Plato proclaims to be composed of various aggregates of triangles), making various compounds of these into what he calls the Body of the Universe. Of all of Plato's works, the Timaeus provides the most detailed conjectures in the areas we now regard as the natural sciences: physics, astronomy, chemistry, and biology.

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