Theaetetus (dialogue)
The Theaetetus (/ˌθiːɪˈtiːtəs/; Greek: Θεαίτητος Theaítētos, lat. Theaetetus) is a philosophical work written by Plato in the early-middle 4th century BCE that investigates the nature of knowledge, and is considered one of the founding works of epistemology. Like many of Plato's works, the Theaetetus is written in the form of a dialogue, in this case between Socrates and the young mathematician Theaetetus and his teacher Theodorus of Cyrene. In the dialogue, Socrates and Theaetetus attempt to come up with a definition of episteme, or knowledge, and discuss three definitions of knowledge: knowledge as nothing but perception, knowledge as true judgment, and, finally, knowledge as a true judgment with an account. Each of these definitions is shown to be unsatisfactory as the dialogue ends in aporia as Socrates leaves to face a hearing for his trial for impiety.
As one of the major works of Plato's theory of knowledge, the Theaetetus was influential on Platonism from at least the time of the Skeptical Academy of the 3rd century BCE through the Neoplatonism of the 6th century CE. It has also been the subject of increased attention in modern times as a result of its influence on Edmund Gettier, who challenged the existing definitions of knowledge as a "justified true belief" in a paper that investigated Plato's theory of knowledge as outlined in this work.
Date and setting[edit]
The Theaetetus is one of the few works of Plato that gives contextual clues on the timeline of its authorship: The dialogue is framed by a brief scene in which Euclid of Megara and his friend Terpsion witness a wounded Theataetus returning on his way home after from fighting in an Athenian battle at Corinth, from which he apparently died of his wounds. Euclid tells his friend that he has a written record of a dialogue between Socrates and Theaetetus, which occurred when Theaetetus was quite a young man. The dialogue is then read aloud to the two men by a slave owned by Euclid.
The exact timeline of which battle at Corinth has been a matter of some disagreement between scholars: it has generally been presumed that the battle occurred in 369 BC; when Theaetetus would have been in his late forties, but more recently, scholars including Debra Nails have argued that the battle referenced in the dialogue was a different battle in Corinth that occurred much earlier, in 391 BC, when Theatetus would have been in his late 20s.[1]
As far as internal characteristics, the dialogue is considered to be similar to the "earlier" dialogues of Plato, such as the Euthyphro or the Crito, in that Plato's Socrates discusses the nature of knowledge in the Theaetetus without giving any of his own views, and the dialogue ultimately ends in aporia without a satisfying answer. However, it also resembles many of the more philosophically complex "later" dialogues such as Parmenides, Phaedrus and the dialogues Sophist and Statesman which serve as a narrative sequel.
Socrates, Theaetetus, and Theodorus reappear the following day in the Sophist an apparent continuation of the conversation contained within the book of Euclid, where they are also joined by an unnamed Eleatic stranger and a boy also named Socrates.
Significant references in the dialogue[edit]
In this dialogue, Socrates refers to Epicharmus of Kos as "the prince of Comedy" and Homer as "the prince of Tragedy", and both as "great masters of either kind of poetry".[note 1] This is significant because it is one of the very few extant references in greater antiquity (Fourth century BCE) to Epicharmus and his work. Another reference is in Plato's Gorgias dialogue.
The dialogue references the Trial of Socrates, which takes place in 399 BCE and is set right. At the end of the dialogue, as Socrates is leaving to face a hearing at the Porch of the King Archon, he agrees to meet Theaetetus and Theodorus in the same place the following day, a conversation that is recounted in the Sophist and Statesman dialogues. The dialogue Euthyphro also is set on the same day, and would have occurred immediately after the Theaetetus, as it occurs outside the Porch of the King Archon as Socrates awaits his hearing.
The dialogue includes the earliest reference to The Astrologer who Fell into a Well, one of Aesop's fables, in which the pre-Socratic philosopher Thales, who is known for his work in astronomy and his successful prediction of a solar eclipse. In the fable, Thales is so distracted by the stars that he forgets the ground below him, and proceeds to trip over a well.
Legacy[edit]
Later Platonism[edit]
The Theaetetus was a popular dialogue in classical antiquity. Writing in the 1st century BCE, the Middle Platonist Eudorus of Alexandria references the definition of a philosopher as a "likeness to a god"[ao] and uses it to justify his synthesis of Platonism with Pythagorean teachings on virtue.[7] One of Eudorus's contemporaries, Philo of Alexandria also quoted from it frequently, implying that he considered it an important work.[7] The Theaetetus was also the subject of many philosophical commentaries. The earliest surviving Platonic commentary, dating from between the 1st century BCE and the 2nd century CE, is a commentary on the Theaetetus, which goes into detail on the nature of knowledge outlined in the work and compares it to the definitions of knowledge outlined in the Meno.[8] The Theaetetus is also referenced frequently by Alcinous in his Handbook of Platonism.[9]
In Late antiquity, the work was included in the Neoplatonic curriculum of twelve dialogues developed by Iamblichus, where it was preceded by the Cratylus, and considered a theoretical work on logic.[10]
Gettier problems[edit]
In the 20th century, the dialogue and its definition of knowledge as a "Justified True Belief" were investigated by Edmund Gettier, who investigated Platonic epistemology as related in the Theaetetus and the Meno is his work "Is Justified True Belief Knowledge (1963)" where he develops the Gettier problem, an example of the type of scenario which challenges the notion that a justified true belief is the same thing as knowledge.
The Theaetetus has been translated into English along with the rest of the Works of Plato
