Κρατύλος
Δελφῖνα νήχεσθαι διδάσκεις: ἐπὶ τῶν ἐν ἐκείνοις τινὰ παιδοτριβούντων, ἐν οἷς ἤσκηται → Teaching dolphins to swim: is applied to those who are teaching something among people who are already well versed in it
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. 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 (Sedley). Aristotle states that Cratylus influenced Plato by introducing to him the teachings of Heraclitus, according to MW. Riley.
Russian (Dvoretsky)
Κρατύλος: ὁ Кратил (ученик Гераклита, учитель Платона; его именем назван платоновский диалог «О сущности слова») Plat., Arst., Diog. L.
Translations
ar: كراتيلوس; ca: Cràtil; de: Kratylos; en: Cratylus; eo: Kratilo; es: Crátilo; et: Kratylos; fa: کراتیلوس; fi: Kratylos; fr: Cratyle; gl: Crátilo; is: Kratýlos; it: Cratilo; ja: クラテュロス; kk: Кратил; la: Cratylus; nl: Cratylus; oc: Cratil; pl: Kratylos; pt: Crátilo; ro: Cratylos; ru: Кратил; uk: Кратил; zh: 克拉底魯篇