Cratylus is the name of a dialogue by Plato. Most modern scholars agree that it was written mostly during Plato's so-called middle period. In the dialogue, Socrates is asked by two men, Cratylus and Hermogenes, to tell them whether names are "conventional" or "natural", that is, whether language is a system of arbitrary signs or whether words have an intrinsic relation to the things they signify.
Plato; 428/427 or 424/423–348/347 BC) was an Athenian philosopher during the Classical period in Ancient Greece, founder of the Platonist school of thought, and the Academy, the first institution of higher learning in the Western world.