Cratylus

Are names natural, or merely conventional? Cratylus claims that every thing has a correct name by nature, while Hermogenes thinks names are only agreed labels. Socrates, joking that he has been inspired by a priest named Euthyphro, examines both views, proposing dozens of playful and sometimes absurd derivations of Greek words, from the names of gods and heroes to the elements, and finally argues that to know the truth we should study things themselves rather than their names.

Written in the early fourth century BC, the Cratylus is the first work of Western philosophy devoted to language, and its questions are still debated. It is given in Benjamin Jowett's translation, though much of the Greek wordplay inevitably slips away in English. Read Plato's Theaetetus and Sophist.

Plato (c. 428–348 BC) was born into an aristocratic family in Athens and became the devoted student of Socrates. After his teacher's trial and execution in 399 BC, he travelled, returned to Athens and founded the Academy, a school that lasted for centuries and counted Aristotle among its students.

Almost all his writings are dialogues in which Socrates questions his fellow citizens about justice, love, knowledge and the soul, from the Apology to the Symposium and the Republic. Known to Arab philosophers as Aflatun, he was read closely by al-Farabi and Ibn Rushd, and Western philosophy has been called a series of footnotes to him.