Kratylos of Athens

A sophist who lived around 410 B.C.E.

He developed an extreme form of Heracliteranism and according to Aristotle influenced the young Plato to think there could be no knowledge of the unstable physical world.

In Plato's Kratylos (also spelled: Cratylus) he was shown defending the natural correctness of names--a development of Heraclitus' view that a thing's essence is often revealed in its name. Aristotle asserted that he also went beyond Heraclitus in saying that you could not step even once into the same river, and that he ultimately avoided speech and merely pointed.

Kratylos seems to have been an extravagant and somewhat uncritical person, who must have found difficulty in reconciling his exaggerations of Heraclitus' beliefs in the ultimate impermanence of objects and the signifiance of some names. There are points which suggest that Plato's interpretation of Heraclitus as having posited constant and universal physical change was derived rather from Kratylos' exaggerated version.

See also: Cratylus