Cratylus is a Socratic dialogue composed by Plato during either his first transitional or the middle period. The topic of the dialogue is the correctness of names.

Scenery of the dialogue

The dialogue, which lacks any reference to the dramatic date or place, plays out among three persons: Socrates, Hermogenes and Cratylus. The dialogue starts in medias res, when Hermogenes calls on the passerby Socrates to contribute his cast of mind to an ongoing discussion.

Hermogenes is included, both by Plato and Xenophon, in the circle of Socrates’ intimate students. According to Aristotle (Metaph., 987a32–b7, 1010a7–15), Cratylus not only espoused the Heracletean doctrine of eternal flux, but also influenced young Plato before the latter became a pupil of Socrates.

Structure and conten

A. Introduction to the problem and refutation of conventionalism

At the offset of the dialogue (383a-384e), Hermogenes wraps up his previous exchange with Cratylus and heralds the discussion that will follow: On the one side, the latter discussant claims that correct is the name that each thing possesses by nature (naturalism); on the other, the former discussant concedes that the correctness of the relation between names and their bearers is established upon agreement (conventionalism).

Hermogenes’ extreme relativism, which allows for the correctness of any arbitrarily imposed name by any individual, provides the occasion for Socrates to brush conventionalism aside (385a-386e): should liars exist, then we cannot accept that their statements about what is the case are true, neither that the names they employ are correct. This criticism suggests that things have a being of their own, which bears on their own nature and not on our perspective.

B. Presentation of naturalism

Now, Socrates moves on to make a case for naturalism (386e-427d). His thesis can be divided into two arguments:

(1) The general argument for naturalism (386e-390e) 

The general argument for naturalism (386e-390e), which is mounted by way of analogy: as it is the case with things, it is also the case with actions (weaving, cutting, burning), including the act of speaking, to be performed according to their own nature. Names are the instruments of speech, and they are produced by the lawgiver (nomothetes)/namegiver. He devises them by looking unto both the generic and the specific form of a name which is naturally appropriate to the object to be named. This congruity between the form of the name and the name embodied in letters and syllables establishes the criterion for the name’s correctness. Lastly, the lawgiver’s work is supervised and assessed by the dialectician, whose knowledge over the use of names appoints him to the task.

In what follows, Socrates is coming away with a flow of etymologies by which he attempts to confirm that the meaning of each name discloses the nature of its bearer. In the course of his etymologies, Socrates stumbles upon the analysis of the first (simple, elementary) names. When he then decides to elaborate on their origin, the theory gives way to:

(2) The mimetic argument for naturalism (421c-425b).

First are the names which cannot be reduced to any simpler names; and also the ones that generate the secondary, the derivative names. Their correctness depends on whether they sufficiently imitate the object they name (and not on their correspondence with the specific form of the name). This second argument closes with Socrates tentatively exhibiting (426b-427d) the mimetic power inherent in some phones – all of which illustrate that things are carried around in eternal flux

C. The limits of Naturalism and of the doctrine of eternal flux

Cratylus, the exponent of naturalism, replaces Hermogenes as Socrates’ partner in the last part of the dialogue (427d-440e).

Now, Socrates takes issue with naturalism and gradually whittles it down (427d-437d): names can either be true or false according to their level of similarity with objects. At any rate, however, a certain degree of dissimilarity is indispensable lest names duplicate objects by becoming identical with them. (This sounds distinctly like a remedy of conventionalism: insofar as the congruity of names and objects is not apparent, the relation between nominators and nominees must be agreed upon). In order to illustrate the ambiguity inherent in the process of etymologizing, Socrates re-works through some of his previous etymologies to the effect of putting forward a different meaning. Thus, he also points out that the lawgiver may have set the names down falsely in the first place.

Finally, Socrates claims that true knowledge cannot be derived from names but from the things themselves. Assuming that the source of knowledge was reversed, we wouldn’t be able to explain whence the givers of the first names drew knowledge of the things they imposed those names on. That said, it is impossible to gather any knowledge from things full of flux and generation (439c-440e): anything susceptible to eternal change does not exist as a specific thing, and therefore it cannot be named or known.

By the end of the dialogue, Socrates admits perplexity, and prompts his interlocutors to reflect further on the vexed questions.

Date of composition

Throughout the dialogue, Socrates takes a particular interest in topics such as the relation of language to reality; the mapping of the division of letters and names onto the division among various kinds of being; the doctrine of eternal flux; and finally Protagorean relativism. All of these themes orient the dialogue towards the late period – although the same questions are discussed there in more detail. On the other hand, the somewhat undeveloped presence of the Forms suggests a classification among the first transitional or the middle period.


In walking through the dialogue we are inclined to ask whether any argument at all endures Socrates' all-around dialectic assault, or if they all wither away in a sceptic upshot.

Some crucial notions figure prominently in the development of the naturalistic thesis: Teaching is coupled with communication and presupposes that names carry distinct meanings and thus signify distinct things. The lawgiver coins names under the supervision of the dialectician who knows their applicability. Finally, Socrates distinguishes between two forms that the lawgiver must look upon in crafting his names: (1) the specific form of a name: that is, the semantic content that is naturally endowed to the object for which the name is coined. The semantic content is the natural form of the object; a form that will turn into a name as soon as it is embodied in phones and letters. The moment this specific name is imposed, it simultaneously embodies (2) the generic form of name: that is, the capacity to distinguish the object it names from other objects, and to declare this distinction in communication.

In the second argument of the naturalistic thesis, Socrates claims that first names are (or should be) direct imitations of objects. This permutation undermines the role of the semantic content (the specific form of name) in the coinage of a name: why, in naming an object, should we take into consideration the semantic content and not the very object itself?

The answer is implied in the third part of the dialogue, where Socrates laid bare the cognitive uncertainty of drawing knowledge from names set down by a potentially mistaken namegiver. The only way to guard ourselves from the illusions gestated in language is to implement the method of someone who knows how to use it, that is the dialectician. It is he who will examine, by means of questions and answers, if the names we use divide up/determine reality in a reasonable fashion. But in order to measure the congruity between the division of names and things (424b7-425a5), we must postulate the dialectician’s a priori access to the things themselves (438d2-439b9). And this access calls the question: if things are subject to constant change, as Cratylus has it, how can the dialectician acquire any knowledge of them?

Indeed, the doctrine of eternal flux entails the impossibility of knowledge. However, in the course of the dialogue, there was one thing, whose firmness, stability and changelessness was not prompted to doubt: the semantic content which is ascribed to objects by nature. On such a conception, the knowledge of the things that the dialectician will use to measure up the correctness of names and language can only be supplied through knowledge of the immutable ideas.

Author: Ioannis Tellios
  • Ademollo, F. The Cratylus of Plato. A Commentary. Cambridge, 2011.
  • Sedley, D, Plato’s Cratylus. Cambridge, 2003.
  • Kretzmann, N. American Philosophical Quarterly. 1971.
  • Kentrotis, G. Plato, Cratylus. Athens, 2001.
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