Plato was an Athenian philosopher during the Classical period in Ancient Greece and the founder of the Academy, the first institution of higher learning in the Western world. He is widely considered the pivotal figure in the history of Ancient Greek and Western philosophy, along with his teacher, Socrates, and his most famous student, Aristotle. Alfred North Whitehead once noted: "the safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato."
The Theaetetus is one of Plato's dialogues concerning the nature of knowledge, written circa 369 BCE.
Hippias of Elis was a Greek sophist, and a contemporary of Socrates. With an assurance characteristic of the later sophists, he claimed to be regarded as an authority on all subjects, and lectured on poetry, grammar, history, politics, mathematics, and much else. Most of our knowledge of him is derived from Plato, who characterizes him as vain and arrogant.
Menedemus of Eretria was a Greek philosopher and founder of the Eretrian school. He learned philosophy first in Athens, and then, with his friend Asclepiades, he subsequently studied under Stilpo and Phaedo of Elis. Nothing survives of his philosophical views apart from a few scattered remarks recorded by later writers.
Cebes of Thebes was an Ancient Greek philosopher from Thebes remembered as a disciple of Socrates. One work, known as the Pinax (Πίναξ) or Tabula, attributed to Cebes still survives, but it is believed to be a composition by a pseudonymous author of the 1st or 2nd century CE.
Aristides was an ancient Athenian statesman. Nicknamed "the Just", he flourished in the early quarter of Athens' Classical period and is remembered for his generalship in the Persian War. The ancient historian Herodotus cited him as "the best and most honourable man in Athens", and he received similarly reverent treatment in Plato's Socratic dialogues.
Epicharmus of Kos or Epicharmus Comicus or Epicharmus Comicus Syracusanus, thought to have lived between c. 550 and c. 460 BC, was a Greek dramatist and philosopher who is often credited with being one of the first comic writers, having originated the Doric or Sicilian comedic form. Aristotle writes that he and Phormis invented comic plots. Most of the information about Epicharmus comes from the writings of Athenaeus, Suda and Diogenes Laërtius, although fragments and comments come up in a host of other ancient authors as well. There have also been some papyrus finds of longer sections of text, but these are often so full of holes that it is difficult to make sense of them. Plato mentions Epicharmus in his dialogue Gorgias and in Theaetetus. In the latter, Socrates refers to Epicharmus as "the prince of Comedy", Homer as "the prince of Tragedy", and both as "great masters of either kind of poetry". More references by ancient authors are discussed in Pickard-Cambridge's Dithyramb, Tragedy, Comedy and they are collected in Greek in Kassel and Austin's new edition of the fragments in Poetae Comici Graeci (2001).
Euclid of Megara was a Greek Socratic philosopher who founded the Megarian school of philosophy. He was a pupil of Socrates in the late 5th century BC, and was present at his death. He held the supreme good to be one, eternal and unchangeable, and denied the existence of anything contrary to the good. Editors and translators in the Middle Ages often confused him with Euclid of Alexandria when discussing the latter's Elements.
Stilpo was a Greek philosopher of the Megarian school. He was a contemporary of Theophrastus, Diodorus Cronus, and Crates of Thebes. None of his writings survive, he was interested in logic and dialectic, and he argued that the universal is fundamentally separated from the individual and concrete. His ethical teachings approached that of the Cynics and Stoics. His most important followers were Pyrrho, the founder of Pyrrhonism, and Zeno of Citium, the founder of Stoicism.
Theaetetus of Athens, possibly the son of Euphronius of the Athenian deme Sunium, was a Greek mathematician. His principal contributions were on irrational lengths, which was included in Book X of Euclid's Elements, and proving that there are precisely five regular convex polyhedra. A friend of Socrates and Plato, he is the central character in Plato's eponymous Socratic dialogue.
Idomeneus of Lampsacus was a friend and disciple of Epicurus.
Phaenias of Eresus was a Greek philosopher from Lesbos, important as an immediate follower of and commentator on Aristotle. He came to Athens about 332 BCE, and joined his compatriot, Theophrastus, in the Peripatetic school. His writings on logic and science appear to have been commentaries or supplements to the works of Aristotle and Theophrastus. He also wrote extensively on history. None of his works have survived.
Callias was an ancient Athenian aristocrat and political figure. He was the son of Hipponicus and the daughter of Megacles, an Alcmaeonid and the third member of one of the most distinguished Athenian families to bear the name of Callias. He was regarded as infamous for his extravagance and profligacy.
Phaedo of Elis was a Greek philosopher. A native of Elis, he was captured in war as a boy and sold into slavery. He subsequently came into contact with Socrates at Athens who warmly received him and had him freed. He was present at the death of Socrates, and Plato named one of his dialogues Phaedo.
Aeschines of Sphettus or Aeschines Socraticus, son of Lysanias, of the deme Sphettus of Athens, was a philosopher who in his youth a follower of Socrates. Historians call him Aeschines Socraticus—"the Socratic Aeschines"—to distinguish him from the more historically influential Athenian orator also named Aeschines. His name is sometimes but now rarely written as Aischines or Æschines
Plato was an ancient Greek philosopher, the second of the trio of ancient Greeks including Socrates and Aristotle said to have laid the philosophical foundations of Western culture.
Philipof Opus, was a philosopher and a member of the Academy during Plato's lifetime. Philip was the editor of Plato's Laws. Philip of Opus is probably identical with the Philip of Medma, the astronomer, who is also described as a disciple of Plato.
Ichthyas, the son of Metallus, was a Greek philosopher and a disciple and successor of Euclid of Megara in the Megarian school. He was a colleague of Thrasymachus of Corinth in the school. Ichthyas is described as a man of great eminence, and Diogenes of Sinope is said to have addressed a dialogue to him.
Myrto was, according to some accounts, a wife of Socrates.
Socrates the Younger was an ancient Athenian philosopher. Ancient texts suggest that he was a young student of the elder Socrates and later a cohort of Plato. He is best remembered for his depiction in Plato's Statesman, and scholars have suggested that he had ties to Academic and Pythagorean philosophy.
