In the character of Cratylus, we find a Platonic figure that most closely matches much of our contemporary philosophic challenge, namely the challenge posed by the Analytic philosophers. The dialogue is a dramatic piece, rather than a recounted story by either Socrates or another story-teller, of a conversation taking place between Hermogenes and Cratylus that Hermogenes (not Cratylus) invites Socrates to attend. Hermogenes is struggling with Cratylus’s claim that there is a natural correctness of names for everything that exists. Hermogenes is skeptical of this account, as no one has been able to persuade him that names are determined by anything other than convention and agreement.
In trying to understand his opinion, Socrates discovers that Hermogenes is skeptical of Protagoras, though he has occasionally dabbled in his relativistic thought, and he also rejects Euthydemus. Since Hermogenes accepts that neither account of things is correct, he must admit that there is a fixed nature, or essence, to things and he further admits that there must also be a correlative correct action to each essence or nature. For example in the case of cutting, a man may try to use a hammer or a spoon, but only the tool that is appropriate to its nature will cut another thing. Another case is of burning. Similarly Socrates wonders why speech would not be the same, namely that there is an appropriate name that was given to each thing by a lawgiver, a creator, the founder of a kind of nomos is the founder of the words (recall the task given to Adam in Genesis). Additionally, the lawgiver must be superior to most man be is uncommon. Not every man can be a lawgiver.
Now that they have established the existence of rule-setters who establish new words and names for things. Next question: how do they do it? Where do they look to naming things? Socrates wonders whether the law-giver will look to the nature of a thing -for example will he look to a broken chair or a whole and complete chair? The answer is obviously the latter. If we admit in the affirmative, then it follows that names are not as inconsequential as Hermogenes had initially thought.
They next divide names for things that humans have and the names the gods have. The gods have infinitely more correct names, as evidenced in Homer and the poets, and Socrates argues that we cannot make claims about the gods as it would be impious and uncouth. The philosopher is distinct from the theologian.
The next third of the dialogue is an examination of the etymologies and origins of various words beginning with the Trojan River and other Homeric names and heroic names, the Hesiodic heroic, and common words like humans, soul, body, mind, gods names, sun, moon, fire and water, seasons, wisdom and knowledge, justice, craft, courage, virtue and vice, good, bad, truth, falsehood, opinion, being, and name. Next they divide the words into the symbols -vowels and consonants and so on, along with the meaning behind the sound of each letter. Naming a thing is a kind of ‘mimesis’ or imitation, similar but distinct from a painting.
For the final portions of the dialogue, Cratylus and Socrates engage with one another and Socrates makes the question that there is such a thing as a fixed notion of goodness, justice, and so on. However, Cratylus agrees with Heraclitus’s embrace of unceasing motion argument. Socrates implores him to think more on it, and he claims that he already has and Cratylus hopes that Socrates will think on these matters for the next time they meet, as well.
The dialogue touches on some of the major questions and problems that arise for the Analytic philosophers in their obsession with linguistics -whether or not there exists a relationships between the sign and the thing in itself, or whether the names we have for things are purely meaningless conventions that have no inherent purpose.