Rafael. The School of Athens.

Plato stands center left, next to Aristotle.
Born:428 BC
Died:348 BC (aged 80)

Plato was a philosopher in classical Greece. He was also a mathematician, student of Socrates, author of many of the Socratic dialogues, and founder of the Platonic Academy in Athens. Aristotle was his most famous student.


1   Philosophy

Plato was a `moral realist`_, an `objectivist`_, as opposed to a `moral subjectivist`_ or `relativist`_. In other words, Plato think that moral terms such as "good", "right", and "just" designate real facts whose status is objective-- independent of an individual's or a culture's opinions, beliefs, customs, or traditions. The moral relativist, on the other hand, believes that the truth status of morality depends upon an individual's or a culture's beliefs, customs. [1]

Plato think there certainly are moral facts and that humans can know them. He argues for precisely this point in many of his dialogues; in others he assumes it. [1]

1.1   Themes

1.1.1   Aporia

Aporia is a deadlock, where no further progress is possible and the interlocutors feel less sure of their beliefs than they had at the start of the conversation. In Plato’s early dialogues, aporia usually spells the end.


In Plato’s early dialogues, Socrates refutes the accounts of his interlocutors and the discussion ends with no satisfactory answer to the matter investigated. In the Republic however, we encounter Socrates developing a position on justice and its relation to eudaimonia (happiness).

The dialogue explores two central questions: what is justice, and what is the relation of justice to happiness?

1.1.2   Anamnesis

Anamnesis is the idea that humans poses innate knowledge and that learning consists of rediscovering that knowledge from within.

1.1.3   Hypomnema

Hypomnema is a Greek word that is translated into English as a reminder, a note, a public record and other variations.

Plato recognized the new status of writing as a device of artificial memory.

2   The Republic

Socrates and Glaucon visit Piraeus, a port of Athens, to pray to the Thracian goddess Bendis. [2] On their way back home to the city after the festival, Polemarchus, Glaucon's brother Adeimantus, and Niceratus stopped them, and Polemarchus invited them to supper at house while they waited for a torch-race later that night. There they join Polemarchus's brother Lysias and Euthdemus, Thrasymachus, Charmantides, Cleitophon, and Polemarchus' aging and wealthy father, Cephalus.

Cephalus welcomes them and Socrates asks him about old age. Cephalus explains old people complain about how they have lost many things to old age. Cephalus says that's not the right cause, since he doesn't feel the same way, and that the real cause is character, and that even young people face face the same problems.

Cephalus explains that Sophocles_, when asked whether he was still able to have sex with women now that he was old, replied that he couldn't but that he called sex a "frenzied and savage monster". Cephalus thinks this was wise and that old brings peace and freedom. Desire can be a kind of master; once you no longer have desire, you can finally relax.

Cephalus explains people don't believe him because he's wealthy, which has some truth to it: you need to be both wealthy and at peace. Cephalus explains the greatest blessing of his wealth is that he doesn't have to worry about any unpaid debts so close to death, when many people normally get nervous (whether because of old age or because they know something about death as they approach it).

Socrates ask Cephalus whether justice was merely paying debts. Cephalus leaves to continue making sacrifices and asks his son Polemarchus to continue the argument. Polemarchus states according to Simonides that the repayment of a debt is just. Socrates point though that it wouldn't be just to return a deposit of arms to a person who is not in his right mind, to which Polemarchus agrees. Polemarchus also agrees that enemies are to receive what we owe them.

Polemarchus suggests that Simonides meant that friends owe friends good thing, not bad things. And further that Simonides would say we owe enemies what they deserve, and what they deserve is evil. So Simonides, the poet, actually meant: justice is the giving to each man what is proper to him (good to friends and evil to enemies), and this he term a debt.

If medicines give drugs to human bodies, and cooking gives seasoning to food, then justice gives good to friends and evil to enemies. And if the physician if best to give good to friends and evil to enemies in time of sickness, and the captain when on a voyage, then the just man is is able to harm to his enemies and good to his friend in going to war against one and in making alliances with the other. And while when a man is well, or not on a voyage, there is no need of a physician or captain, there is still a need for justice even in times of a peace. Justice is useful for contracts during peace. The just man is useful when you want to keep a deposit safely; justice is useful of all things when they are useless and useless when they are useful.

But he who is a good keeper of anything is also a good thief. So if the just man is good at keeping money he is good at stealing it.

Polemarchus doesn't know how to respond and reasserts justice is do good to friends and evil to enemies. Socrates ask are friends actually good people or are they just people whom we think are good? If people err about good and evil, it it more proper to say that we ought to do good to the just and harm to the unjust, which may mean doing evil to friends and good to enemies. This is different from what Simonides says so Polemarchus says we need to interpret friend and enemy not only as those who seem good or bad, but who actually are as they seem; that is, the good are our friends, and the bad are our enemies.

Should the justice injure anyone at all? If hurting a thing makes it worse, not better, then hurting a man makes him less virtuous and less just. But you can't make someone unjust by justice (just like the musician can't make someone unmusical through music) so it can't be just to harm your enemies. This contradicts Polemarchus' original definition, and convinces him.

Discussion between Socrates and Thrasymachus follows.

Thrasymachus, who had been want to interrupt the whole time, criticizes Socrates. Thrasymachus challenges Socrates to money if he can define justice in a better way than Socrates, but Socrates doesn't have it so Glaucon offers to pay it for him. Thrasymachus accuses Socrates of learning from other people without teaching anything in return, which Socrates objects to.

Thrasymachus thought he had an excellent answer and would distinguish himself. He claims that justice is "nothing else than the interest of the stronger".

Gell, he said, have you never heard that forms of government differ; there are tyrannies, and there are democracies, and there are aristocracies?

Yes, I know. And the government is the ruling power in each state? Certainly.

And the different forms of government make laws democratical, aristocratical, tyrannical, with a view to their several interests; and these laws, which are made by them for their own interests, are the justice which they deliver to their subjects, and him who transgresses them they punish as a breaker of the law, and unjust. And that is what I mean when I say that in all states there is the same principle of justice, which is the interest of the government; and as the government must be supposed to have power, the only reasonable conclusion is, that everywhere there is one principle of justice, which is the interest of the stronger.

It's just for subjects to obey their rulers, but the rulers of states are liable to err. Then in making laws they sometimes make them rightly and sometime not. When they make them rightly, they make them agreeable to their interest and when they are mistaken, contrary to interest. So justice is sometime obedience to the interest of the stronger is and sometimes the reverse. (ie if rulers are mistaken about their own interest in what they command, the stronger may command the weaker who are his subjects to do what is not for his own interest)

Do you suppose that I call him who is mistaken the stronger at the time when he is mistaken? ... Do you mean, for example, that he who is mistaken about the sick is a physician in that he is mistaken? or that he who errs in arithmetic or grammar is an arithmetician or grammarian at the me when he is making the mistake, in respect of the mistake? No artist or sage or ruler errs at the time when he is what his name implies; though he is commonly said to err, and I adopted the common mode of speaking.

We should say that the ruler, in so far as he is the ruler, is unerring, and, being unerring, always commands that which is for his own interest; and the subject is required to execute his commands; and therefore, as I said at first and now repeat, justice is the interest of the stronger.

Every art has an aim, and the interest of any art is the perfection of it. Some art cares for themselves, and other care for others (e.g. medicine for the body, horsemanship for the horse). The art are the rulers of their own subjects.

Socrates argues that the doctor is a care-take first, not a money-maker. And likewise, a ruler cares for their subjects first, not themselves. Thrasymachus disagrees, arguing rules are more like shepherds, who definitely do not take care of sheep for their own good.

The just is always a loser in comparison with the unjust. The unjust gains advantage in contracts, in paying taxes, and in general receiving things. This occurs most clearly in a tyranny, where the criminal is the happiest of men and those who refuse to do injustice are the most miserable. Injustice on a sufficient scale has more strength than justice.

Thrasymachus tries to leave, but the company wouldn't let him.

Socrates say he does not believe injustice to be more gainful than justice.

Socrates ask why men do not take lesser offices willingly without payment if they govern for themselves and not others.

Medicine is not the art of receiving pay because a man takes fees when he is engaged in healing. And the good of each art is confined to the art. Artists must use a separate art, the art of pay, to receive money.

3   The Symposium


Anselm Feuerbach. Plato's Symposium.

Plato wrote the Symposium in 360 BC.

Discusses the nature of beauty, love, and knowledge. It is the origin of the concept of Platonic love.

Love is examined in a sequence of speeches by men attending a symposium, or drinking party.

Socrates and Apollodorus go to the house of Agathon. Socrates entered late while everyone else was eating supper. The earlier day there was a party. Nobody wants to drink too much, and instead they agree to conversation. Eryximachus suggested that they have conversation instead about love.

Phaedrus goes first. He claims Love is the eldest of gods. He claims lovers will be more pained at doing a dishonorable act in front of their lover; if an army could be made of lovers, they would abstain from all dishonors and overcome the world. Or who would desert his beloved or fail him in the hour of danger? Love will make men dare to die for their beloved—love alone; and women as well as men.

Of this, Alcestis, the daughter of Pelias, is a monument to all Hellas; for she was willing to lay down her life on behalf of her husband, when no one else would, although he had a father and mother; but the tenderness of her love so far exceeded theirs, that she made them seem to be strangers in blood to their own son, and in name only related to him

3.1   Pausanias

The next speaker was Pausanias. He claims there is more than one kind of love.

Pausanias distinguishes between a heavenly Aphrodite and a common Aphrodite. The heavenly Aphrodite has no mother but her father is Uranus.

Pausanias points out that there are two kinds of Aphrodite, the goddess of love. First, there is Heavenly Aphrodite, the daughter of Uranus, with whom he associates "Heavenly Love." Second, there is Common Aphrodite, daughter of Zeus and Dione, who is considerably younger than Heavenly Aphrodite, and with whom he associates "Common Love."

Pausanias was an ancient Athenian of the deme Kerameis, and was the lover of the poet Agathon. Although Pausanias is given a significant speaking part in Plato's Symposium, very little is known about him.

Now actions vary according to the manner of their performance. Take, for example, that which we are now doing, drinking, singing and talking—these actions are not in themselves either good or evil, but they turn out in this or that way according to the mode of performing them; and when well done they are good, and when wrongly done they are evil; and in like manner not every love, but only that which has a noble purpose, is noble and worthy of praise.

the actions of a lover have a grace which ennobles them; and custom has decided that they are highly commendable and that there no loss of character in them

4   The Academy



The school, founded by Plato around 387 B.C.E., was named the Hecademia and later Academia after the nearby sanctuary dedicated to the hero Hecademus. In Plato’s time, the area occupied about 1.5 hectares (about 3.5 acres) and was reached by leaving the city of Athens by the Diplon gate and walking along a road flanked by a public cemetery. The Gymnasium was a rectangular complex, approximately 200 feet long and 100 feet wide.

The site was excavated in 1929-39 and a plan of the main building was published.

Plato’s Academy is now a public park in a not particularly nice part of town. It is just next to Colonus, Sophocles’ birthplace and, according to the legend he helped to invent, the final resting place of Oedipus.

The Academy is literally a museum, a temple or a sacred space, an association that is continued in Aristotle’s Lyceum and on into the most famous library of the ancient world: the Museum of Alexandria (which contained its famous and famously destroyed library), founded by the Ptolemies after 297 B.C.E.

Behind the muses was the main building of the Academy, divided into a number of rooms. We are not exactly sure of their function, but it is highly likely that they were used for teaching and were equipped with boards, writing materials, geometric instruments, globes and celestial spheres. But the center of the Academy was the library, well stocked with texts, stacked papyri, possibly with labels, on which the titles were inscribed. The library was the first of its kind in Athens.

To delve a little deeper, here’s an intriguing question: What was on the shelves of Plato’s library? What had he read and what did he give his students to read? We can only guess, but it’s likely there would have been writings on mathematics, geometry and medicine, volumes by Homer and Hesiod. From the evidence of the Dialogues, it is clear that Plato had read the long-lost works of pre-Socratic thinkers like Heraclitus (“On Nature”) and Anaxagoras (“Nous”), and texts by the Eleatic thinkers like Parmenides. It is also said that Plato made an extremely expensive purchase of three works by Pythagoras. There would also have been works by the Sophists, whom Plato loathed, and possibly the widely read works of the atomists, like Democritus, whom Plato completely ignored, possibly out of envy.

In addition to the bookshelves storing these texts, there was possibly a wooden dais for the readings, lectures and discussions that took place daily. Most intriguing perhaps in the design of the Academy is the House of the Reader, or anagnostes. It is said that a young Aristotle served as Reader or Lector during his 20 years in the Academy. Apparently, he was nicknamed Nous or Mind by Plato, which seems appropriate. It would appear that the agnostic Reader was responsible for reading aloud every treatise submitted for publication in the Academy.

What is striking is the wholly geometric nature of the design of the Academy, which my new friend, Mr. Staikos, thinks was due to the influence of the Pythagorean school that Plato encountered on his trips to Sicily and that had been revived by Archytas of Taras, a friend of Plato’s and some say the model for the philosopher king described in the Republic. Legend has it that the motto of the Academy, written over the entrance, was “Let no one ignorant of geometry enter.”

But the Academy was also a privately funded research and teaching facility, situated outside the city. Most of us have a rather whimsical idea of philosophy as a bunch of men in togas having a chat in the agora. And we think of Socrates as a gadfly, philosophizing in the street and somehow speaking truth to power. It’s an attractive idea. But this is the literary conceit of philosophy — one that is still in circulation today. It is the fiction that Plato wants his readers to believe.

Behind that fiction stands the library, the editing and copying rooms, and the entire research engine of the Academy, which was devoted to the careful production and dissemination of knowledge through texts and teaching. Much as we may flinch at the idea, philosophy has always been academic and linked to the activity of schools since its inception.

At this point, a rather vulgar question comes to mind: Who paid for the Academy? According to Mr. Staikos, the cost of construction is estimated at 25 to 30 talents. As a wild modern-day estimate, we could say that the Academy cost a couple of hundred thousand dollars to build. How did Plato get this money? We don’t know. It is said that he was captured on his return trip from Sicily in 387 and sold as a slave on the island of Aegina, which Athens was at war with at the time. According to one account, Anniceris of Cyrene paid a ransom of 30 minas. But he refused to be paid back after Plato was returned to Athens, and the money was used to pay for a plot of land where the Academy was built.

Although the splendidly unreliable Diogenes Laertius says that Plato possessed no property other than what is mentioned in his will, he received a large sum of money from Dionysius I. Plato had a significant fund of money at his disposal (the exorbitant figure of 80 talents is mentioned). Indeed, Plato is also said to have had a banker called Andromedes. In other words, Plato was rich and had wealthy patrons and very probably wealthy students.

We are less attracted to the idea of the wealthy Aristocratic philosopher sequestered in his research facility and making occasional overseas trips to visit foreign tyrants than the image of the poor, shoeless Socrates causing trouble in the marketplace, refusing to be paid and getting killed by the city for his trouble. But our captivation with this image, once again, is overwhelmingly Plato’s invention.

And behind his extraordinary inventiveness, Plato performs a characteristic disappearing trick. Truth to tell, we know very little about Plato. According to Plutarch, he was a lover of figs. Big deal! Plato is mentioned only a couple of times in the many dialogues that bear his name. He was present at Socrates’ trial but — in a beautifully reflexive moment that he describes in the Phaedo — absent from the moment of Socrates’ death, because he was sick.

In fact, we don’t even know that he was called Plato, which might have been a nickname. Laertius claims that he was actually called Aristocles, after his grandfather. “Plato” is close to the word “broad” in Greek, like the broad leaves of the platanos or plane tree under which Socrates and Phaedrus sit and talk about eros. Some think that Plato was so called because he was broad-shouldered because of his prowess in wrestling.

Plato worked at the Academy until his death in 347 B.C.E., interrupted only by two more extended trips to Sicily. The Academy survived for a few more centuries until it was destroyed by the Roman general Sulla_ in 87 B.C.E. during the sack of Athens.

5   References

[1](1, 2) Approaching Plato
[2](1, 2) Antonis Coumoundouros. Plato: The Republic. Internet Encylcopedia of Philosophy.
[3]Simon Critchley. Feb 6, 2019. Athens in Pieces: The Stench of the Academy.