Cratylus (/ˈkrætɪləs/ KRAT-il-əs; Ancient Greek: Κρατύλος, Kratylos) is the name of a dialogue by Plato. Most modern scholars agree that it was written mostly during Plato's so-called middle period.[1] 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.
The individual Cratylus was the first intellectual influence on Plato.[2] Aristotle states that Cratylus influenced Plato by introducing to him the teachings of Heraclitus, according to M. W. Riley.[3]