Cratylus may at first sound a little archaic to our ears because it asks a question that seems to border on a magical view of the power of names -- are things 'correctly' named? Even to wonder whether there could be some intrinsic connection between a 'true' name and the essence of the thing it describes offends our modern certainty in the arbitrariness of linguistic signs. Combine this off-putting question with the fabricated ancient Greek etymology that occupies two thirds of the dialog, and you have the recipe for one of Plato's most boring works. So I won't be spending a ton of time on this one. Still, there are a few interesting points we should cover.
The first third of the dialog stakes out the sides. Hermogenes claims that names are just the result of arbitrary convention, so it makes no sense to call a name better or worse based on some putative correspondence between it and the thing itself. Cratylus, by contrast, claims that only one name belongs to each thing by its nature. In other words, he thinks there must be a one-to-one correspondence between names and things. Socrates questions both of these ideas and ends up somewhere in the middle. He spends the first third of the dialog questioning Hermogenes until he establishes that there must be at least a way of naming that correctly follows the contours of nature. The middle two thirds are devoted to a long etymological analysis showing how the names of Greek gods and heroes, as well as the names for common concepts like justice and wisdom, might be correct. I say "might be" because Socrates continually mentions how unsure he is of his own analysis. He seems to be giving just one example of the type of analysis that he and Hermogenes agreed must exist. In the final third, Socrates comes back to question Cratylus, and convinces him that while there may be some concept of correctness, it goes too far to posit a one-to-one correspondence between each thing and its secret, almost magical, true name.
The conversation with Hermogenes actually starts out in an interesting way that made me briefly wonder if Plato was aiming at a structuralist theory of language avant la lettre. Hermogenes claims that names are arbitrary, so no name can be better or worse than another; the idea of 'correctness' doesn't apply to names. Socrates asks him if he believes that the same logic applies to "things that are". We've seen this latter phrase appear as a noun once before in Phaedrus, and many times (ironically) in the mouths of Euthydemus and Dionysodorus. It's scattered all throughout Cratylus however, and seems to make a number of appearances in the Sophist, Statesman, and Philebus, so we should be attuned to the birth of a new concept. In Phaedrus it explicitly referenced the Forms that souls saw as they progressed through heaven. Here, though it's not explained, it seems to have broadened into something like "things in themselves", each of which then may have a being or essence.
Now, Hermogenes isn't sure whether "things that are", unlike names, have a fixed and non-arbitrary essence, but Socrates is pretty adamant. He bases his conclusion on two observations. First, morality exists. If there are good men and bad men, wise men and foolish men, then good, bad, wise, and foolish must all refer to some public essence that isn't simply in the mind of the beholder or the momentary state of the men involved. (386d) Giving up essences, Socrates claims would be tantamount to giving up morality. Second, morality exists. We can imagine a world where things have public and objective qualities, but where everything we meet is always a mix of all the qualities. Socrates attributes this idea to Euthydemus with his simultaneous affirmation and refutation of every proposition. But if everything is mixed, then again, we will have to give up our moral judgements about whether a man is either good or bad. We always have to remember that the metaphysical theory of the forms is moral to its core.
SOCRATES: But if neither is right, if it isn't the case that everything always has every attribute simultaneously or that each thing has a being or essence privately for each person, then it is clear that things have some fixed being or essence of their own. They are not in relation to us and are not made to fluctuate by how they appear to us. They are by themselves, in relation to their own being or essence, which is theirs by nature. (386e)
Once Socrates' establishes that "things that are" have some fixed and non-arbitrary essence, it's a short step to convincing Hermogenes that names can't be completely arbitrary either, but have to accord with the nature of the reality that they describe and interact with. After all, any good tool has to itself be structured so as to interact with or grasp on to part of the structure of reality.
SOCRATES: So an action's performance accords with the action's own nature, and not with what we believe. Suppose, for example, that we undertake to cut something. If we make the cut in whatever way we choose and with whatever tool we choose, we will not succeed in cutting. But if in each case we choose to cut in accord with the nature of cutting and being cut and with the natural tool for cutting, we'll succeed and cut correctly. If we try to cut contrary to nature, however, we'll be in error and accomplish nothing. (387a)
At first this suggested to me something close to the theory of science I have maintained. There's no single objective truth about reality that science could converge to. Nevertheless, reality does have some objective structure. Poke it this way or prod it that, and it will respond in characteristic ways. That is, if you want to cut it into small, sharply divided pieces, you need to use a knife. Of course, cutting it up is only one thing you might want to do with reality. So when you stab reality and it really does bleed, your conclusion that "reality is a bunch of sacks filled with blood" isn't wrong, it's just laughably incomplete and partial. Maybe instead of cutting it, you should have combined parts of reality, or squeezed them, or rolled them down a hill, or whatever. Each of these actions would reveal something else about reality that might or might not accord with how it reacted when you cut it. If there is something that corresponds to Objective Reality™ it is just the sum of these various aspects revealed by our various actions that are relevant to our various purposes.
For a while, Socrates continues his tool analogy in a way that seemed to fit with this interpretation. If names are tools, then they must have been created by some craftsman (the rule-setter) for some purpose: "a name is a tool for giving instruction, that is to say, for dividing being." (388c) This seemed to make the 'correctness' of names Socrates had been arguing for a lot less magical and a lot more human and pragmatic. In fact, he goes even further and points out that individual tools are really just instances of some general form of a tool. And what constitutes the correct form of a tool is its usefulness in achieving a particular goal.
SOCRATES: So mustn't a rule-setter also know how to embody in sounds and syllables the name naturally suited to each thing? And if he is to be an authentic giver of names, mustn't he, in making and giving each name, look to what a name itself is? And if different rule-setters do not make each name out of the same syllables, we mustn't forget that different blacksmiths, who are making the same tool for the same type of work, don't all make it out of the same iron. But as long as they give it the same form—even if that form is embodied in different iron—the tool will be correct, whether it is made in Greece or abroad. Isn't that so? HERMOGENES: Certainly.
SOCRATES: Don't you evaluate Greek and foreign rule-setters in the same way? Provided they give each thing the form of name suited to it, no matter what syllables it is embodied in, they are equally good rule-setters, whether they are in Greece or abroad.
HERMOGENES: Certainly.
SOCRATES: Now, who is likely to know whether the appropriate form of shuttle is present in any given bit of wood? A carpenter who makes it or a weaver who uses it?
HERMOGENES: In all likelihood, Socrates, it is the one who uses it. (389d)
Initially I construed this a sort of structuralist account of tools. The pieces of the tool may be constructed of different materials, but as long as they come together in the same form or structure, that internally structured tool can then interact in a particular way with some aspect of the structure of reality. It's not quite "tools are systems of differences", but it seems to move in that direction.
This is probably not how Plato intended it though, as the development of the dialog makes clear. Socrates goes on to say that it is the dialectician -- the one who asks and answers questions as a means of dividing being -- who judges the usefulness of names. At this point the analogy to my interpretation of science begins to break down. Naming is not just one tool among many by which we approach reality, but a tool for "dividing being". And since we know that "things that are" have fixed essences, namely the Forms which gather them together and split them apart dialectically, then we can no longer see names as merely pragmatically structured tools that latch onto one aspect of reality, but are forced to interpret them as signs that represent the structure of some underlying reality. Language is a special tool that represents all the divisions of being.
After he reaches this conclusion about the nature of naming, Socrates moves into the etymological analysis that consumes most of the dialog, and provides examples of how things should be named. These make it even more clear that he conceives of the relationship between name and thing as one of representational identity. Socrates begins by giving plausible stories about why the gods have the names they do by relating the sound of their names to similar sounding words that describe some important aspect of them. For example, Tantalus is so called because he has a stone suspended (talanteia) above his head in Hades, and Ares reminds us of virility (arren) and courage (andreia). He continues by extending this playful etymology to the names of heroes, and then even to words like justice and knowledge and understanding. Along the way, we see a pattern developing, where Socrates associates every positive term with words that suggest unimpeded flow, and every negative term, like, say, 'ugly', with something that restrains or hinders a flow. This allows him to sketch a whole hierarchy of names that are based on primitive or atomic names that relate to stopping and going -- 'ion' ('going'), 'rheon' ('flowing'), and 'doun' ('shackling') (421c). These elementary names are then analyzed not in terms of other names, but in terms of the letters that compose them. In particular, the idea is that these names are derived from the motions of the mouth and tongue mimicking the things they stand for. 'R' is the letter used for things in motion because of its rolling characteristic. 'I' is used for small things that penetrate others. 'Phi', 'S' and 'Z' are used for violent shaking or quaking movements because of the associated expulsion of breath. And so on. Socrates makes an explicit analogy between painting a representative picture by combining certain colors and finding a representative word by combining the characteristics of certain letters. At this point, any analogy to structuralism is completely lost. Letters are not differential signifiers which are in themselves empty, but little atoms of meaning that resemble things in the world.
In the final section of the dialog Socrates returns to finish the other side of the conversation. He began by convincing Hermogenes that names aren't completely arbitrary and meaningful only by convention. He ends by convincing Cratylus that, on the other hand, there is also not a single true name for each thing. Cratylus' position is in fact so extreme that he at first doesn't even allow for the possibility of a name being assigned incorrectly. Since he believes everything has a single true and essential name that functions almost like a magical incantation, if we were to spell it wrong we would actually end up naming a different thing.
CRATYLUS: That's right. But you see, Socrates, when we assign 'a', 'b', and each of the other letters to names by using the craft of grammar, if we add, subtract, or transpose a letter, we don't simply write the name incorrectly, we don't write it at all, for it immediately becomes a different name, if any of those things happens. (432a)
Cratylus demands a one-to-one correspondence between each and every thing and its single possible name. This apotheosis of representation would quickly result in a language just as complex as the world, a map as large as the territory, which would be useless for classifying or manipulating it. We can see now why Socrates didn't push his etymology too far and instead left some playful wiggle room in his names. Names have to be a lossy compression of the world to be useful. They have to be an image of the world, not a perfect double of it.
But this isn't the sort of correctness that belongs to things with sensory qualities, such as images in general. Indeed, the opposite is true of them— an image cannot remain an image if it presents all the details of what it represents. See if I'm right. Would there be two things—Cratylus and an image of Cratylus—in the following circumstances? Suppose some god didn't just represent your color and shape the way painters do, but made all the inner parts like yours, with the same warmth and softness, and put motion, soul, and wisdom like yours into them—in a word, suppose he made a duplicate of everything you have and put it beside you. Would there then be two Cratyluses or Cratylus and an image of Cratylus? (432b)
Socrates goes on to argue that names only have to reproduce the pattern of the thing they name. This pattern could of course be rendered in various languages, or with various combinations of letters within a single language. However, since this pattern is a sort of essence that the name attempts to represent, some varieties will capture that essence better or more accurately than others. So while there's not one true name for everything, we can still say that some names are better or more appropriate than others because their pattern is more like the essence to be represented. In other words, Socrates would have us steer a course directly between Cratylus and Hermogenes.
After he's finally come full circle and outlined his middle road theory of names, Socrates concludes by telling us how none of this naming stuff is terribly important. Names are simply never going to be a completely reliable guide to learning about the things in themselves. The reader may feel somewhat let down to discover that the whole conversation was in vain, but on some level this turns out to be the whole point of the dialog -- we cannot learn about things just by studying their names. Names, after all, are just images, likenesses, a way of painting with sounds. If we want to know, we need to investigate the things themselves.
SOCRATES: So if it's really the case that one can learn about things through names and that one can also learn about them through themselves, which would be the better and clearer way to learn about them? Is it better to learn from the likeness both whether it itself is a good likeness and also the truth it is a likeness of? Or is it better to learn from the truth both the truth itself and also whether the likeness of it is properly made?
CRATYLUS: I think it is certainly better to learn from the truth.
SOCRATES: How to learn and make discoveries about the things that are is probably too large a topic for you or me. But we should be content to have agreed that it is far better to investigate them and learn about them through themselves than to do so through their names. (439a)
As a final illustration of this problem, Socrates recalls his own earlier theory of names which associated positive qualities like beauty and knowledge with names related to continuous motion, and negative qualities with blockages. That theory sits quite poorly with the theory of unchanging Forms that he always argues for. Socrates doesn't make an argument for the Forms here. He points out that if we simply examined names alone, we would be led to believe that everything was flowing and passing away. Since he claims it is at least possible that a fixed Beauty and Good exist, he concludes that in this particularly important case we also cannot use names alone to adjudicate the matter. Now that you've climbed to the top of the word ladder, you can apparently throw it away.