Theaetetus. Sophist

Plato, the great philosopher of Athens, was born in 427 BCE. In his early manhood, he was an admirer of Socrates and later founded the famous school of philosophy in the grove Academus. Much else recorded of his life is uncertain; it is probable that he left Athens for a time after Socrates' execution. It is possible that he also travelled to Cyrene, Egypt, and Sicily. He was likely wealthy and obviously critical of 'advanced' democracy. He lived to be 80 years old. Linguistic tests, including those of computer science, still attempt to establish the order of his extant philosophical dialogues, which are written in splendid prose and reveal Socrates' mind fused with Plato's thought.

In Laches, Charmides, and Lysis, Socrates and others discuss separate ethical conceptions. Protagoras, Ion, and Meno explore whether righteousness can be taught. In Gorgias, Socrates is estranged from his city’s thought, with his fate impending. The Apology (not a dialogue), Crito, Euthyphro, and the unforgettable Phaedo relate the trial and death of Socrates and propose the immortality of the soul. In the famous Symposium and Phaedrus, written when Socrates was still alive, we find the origin and meaning of love. Cratylus discusses the nature of language. The great masterpiece in ten books, the Republic, concerns righteousness and involves education, equality of the sexes, the structure of society, and the abolition of slavery.

Of the six so-called dialectical dialogues, Euthydemus deals with philosophy; the metaphysical Parmenides is about general concepts and absolute being; Theaetetus reasons about the theory of knowledge. Of its sequels, Sophist addresses not-being; Politicus covers good and bad statesmanship and governments; Philebus considers what is good. The Timaeus seeks the origin of the visible universe out of abstract geometrical elements. The unfinished Critias treats the lost Atlantis. Unfinished also is Plato's last work of the twelve books of Laws (Socrates is absent from it), a critical discussion of principles of law which Plato thought the Greeks might accept.

The Loeb Classical Library edition of Plato is in twelve volumes.