The dialogue begins with a dispute between Hermogenes, who argues that words are purely conventional and can be altered at will, and Cratylus, who maintains that names possess an inherent natural correctness. Socrates enters the discussion to challenge both extremes by introducing the concept of the name as an instrument designed for instruction and for distinguishing the essences of things. Through an extensive and often ironic etymological examination, Socrates analyzes the names of gods, heroes, and abstract virtues, attempting to connect them to the Heracleitean principle of universal flux. He demonstrates how early word-makers embedded specific motions and qualities into letters and syllables, treating language as a formative art rather than a random occurrence.
However, Socrates repeatedly warns against trusting etymologies as absolute proofs, noting that inventors of words could be mistaken and that language often contains contradictory assertions about rest and motion. Towards the end, the focus shifts from linguistic analysis to fundamental epistemology, as Socrates argues that things must be known and studied through their own intrinsic nature rather than through the deceptive medium of names. He asserts the existence of absolute, immutable entities like the true beautiful and the true good, which cannot be subject to constant transition or caught in the flux of speech. Ultimately, Cratylus remains inclined towards the philosophy of Heracleitus, while Socrates concludes that true knowledge requires looking beyond the names we use to reality itself.
