Mimesis (Imitation)

Mimēsis — imitation, copying, representation — is one of Plato's most consequential and most ambivalent concepts. In the Wave-1 dialogues it does two distinct kinds of work: in the Cratylus a name is a vocal imitation of a thing's being/essence; in the Sophist the decisive ontology of the image turns on the distinction between likeness-making (eikastikē, faithful copies) and appearance-making (phantastikē, distorted semblances that merely seem right). The corpus's most famous treatment is the Republic's — a characterological critique in Books II–III (imitation shapes the imitator) and the ontological critique of Book X (the three beds: the imitator is "third from the truth").

Key Points

Cratylus: naming as imitation of essence (423b–424b): "a name is a vocal imitation of what it imitates," but sharply restricted — naming imitates ousia (being), not sound, shape, or color, distinguishing it from music, painting, and crude onomatopoeia ("those who imitate sheep… are [not thereby] naming").
The non-duplication principle (Cratylus 431e–433a): a successful image must not duplicate its original — a perfect copy of Cratylus would be "two Cratyluses," not Cratylus and an image. Mimesis is constitutively non-identity.
Sophist: likeness vs. appearance (235d–236c): a likeness (eikōn) keeps the model's true proportions; an appearance (phantasma) "appears the way the thing does but in fact isn't like it," depending on a distorting viewpoint. The whole metaphysical excursus on not-being exists to make phantastikē — and so the sophist — coherent.
The image's ontology forces the not-being problem: to define a phantasma as something that "is not really" what it seems is already to say "what is not" — which is why the Sophist's theory of the image cannot proceed without rehabilitating not-being.
Republic II–III: the characterological critique (376c–398b): mimēsis as a mode of narration (the poet "hiding himself," speaking as a character) vs. pure diēgēsis; the worry is that "imitations … from youth become part of nature" (395d) — rehearsing bad models corrupts the imitator, so guardians may imitate only good ones.
Republic X: the ontological critique (595a–608b): the three beds — the Form (made by a god), the carpenter's copy ("looking to the form"), and the painter's, "an imitation of appearances, not truth." The imitator is "third from the king and the truth" (597e), "knows nothing" of what he imitates, and "consorts with a part of us that is far from reason" (603b). Hence "an ancient quarrel between philosophy and poetry" (607b).
Ion: the inspiration register (the fourth, and the odd one out): in the Ion poets and rhapsodes lack knowledge not because they make twice-removed copies but because they are divinely possessed — "the god… speaks" through an absented intellect (534d). Same verdict as Republic X ("poets know nothing"), different mechanism (theological possession vs. mimetic distance). Homed on poetic-inspiration.
Critias: the audience-relative register (107b–e): the painter analogy adds a distinct axis. The Sophist/Republic grade images by fidelity to the model; the Critias grades the difficulty of the representational act by the critic's competence — we are "harsh critics" of likenesses of the familiar/human and indulgent of the divine/remote, so representing the human is harder. The difficulty is relocated from the object's obscurity to the spectator's expertise. The Critias also stages the ideal city itself as an eikōn (the kallipolis realized in narrative); see claims#plato-republic-timaeus-critias-enacted-paradigm (live claim).

What the Concept Does

Grades images by their fidelity — distinguishing the faithful copy from the deceptive semblance, which lets Plato locate the sophist (and, in Republic X, the poet) as makers of the deficient kind.
Makes the image depend on a gap — both dialogues insist the image is not its original (non-duplication; distorted proportion); mimesis is a relation of likeness-with-difference, not coincidence.

Connections

is developed by correctness-of-names — names as vocal imitation of essence (the Cratylus's mimetic theory of primary names).
requires non-being — the Sophist's appearance-making (phantastikē) is definable only once not-being is rehabilitated as difference.
requires theory-of-forms — an imitation is an imitation of a model; the copy/model structure presupposes the Forms (most explicitly in the Timaeus's cosmos-as-copy).
grounds the model/copy hierarchy inverted by simulacrum — Republic X's god-Form → carpenter-copy → painter-phantasma, together with the Sophist's phantastikē, is the model/copy/simulacrum order Deleuze's "overturning of Platonism" denies; the painter's appearance "that looks like but is not" is the simulacrum Plato subordinates.
is targeted by umdrehung-des-platonismus — demoting the image as "third from the truth" belongs to the two-world hierarchy Nietzsche/Heidegger overturn.
is complemented by poetic-inspiration — the Ion's possession-account is a distinct (non-copying) register by which Plato denies poets knowledge; together they make the Republic X exclusion overdetermined. See claims#plato-poet-lacks-knowledge-two-routes (live claim).
has cross-tradition cousin indirect-language — the non-duplication principle (a coinciding image ceases to be an image) is a structural cousin of MP's expression thesis; but MP's expression is creative/diacritical where Platonic mimesis is reproductive/resemblance-based (a contrast as much as a cousinhood).

Motif Weight & Corpus Recurrence

This concept is the primary corpus-level home for §"image / copy / mimesis / eikōn (the model-copy hierarchy) (Plato)" (a STRUCTURAL motif, 5 Plato sources) and a home for §"being vs becoming / being vs seeming / appearing (phainesthai) (Plato)" (STRUCTURAL, 7 Plato sources). See motifs.md for the current attestation lists, source-level weights, and genealogy / cross-tradition links. Update both this section and the motifs.md entries when corpus weight shifts.

Open Questions

The Platonic registers must be kept distinct, not collapsed into one "theory of mimesis": the Cratylus's naming-as-vocal-imitation, the Sophist's likeness/appearance ontology, the Republic's two critiques (characterological II–III; ontological X), and the Ion's inspiration/possession register (which is arguably not mimesis at all — the possessed poet does not copy but is spoken through). Whether Book X's "third from the truth" is continuous with, or a sharpening of, the Sophist's phantastikē is interpretable either way (Book X is pictorial/poetic; the Sophist general).
Is the Cratylus's "vocal imitation of essence" continuous with the Sophist's image-ontology, or a distinct (linguistic vs. pictorial) sense of mimesis?
The Critias painter analogy vs. the Timaeus's likely story (eikōs muthos): the Timaeus makes the divine/cosmic object the less knowable (so its account is only "likely"), whereas the Critias makes the familiar/human the harder to represent (because audiences are exacting critics of it). Compatible — they fix different parameters (the object's knowability vs. the audience's critical standard) — or a genuine tension in Plato's theory of the eikōn? A deferred claim seed (re-read Timaeus 29b–d before pressing it).

Sources

plato-cratylus — names as vocal imitation of essence (423b–424b); the non-duplication principle (431e–433a).
plato-sophist — likeness-making vs. appearance-making (eikastikē/phantastikē, 235d–236c); the image's dependence on not-being.
plato-republic — the characterological critique (II–III, 392c–398b) and the ontological "three beds" / third-from-truth critique (X, 595a–608b).
plato-ion — the inspiration/possession register (the magnet, enthousiasmos): poetry as divine possession, not copying (530a–542b).
plato-critias — the painter analogy and the audience-relative difficulty of representing the human vs. the divine (107b–e); the city as eikōn (the enacted paradigm).
plato-menexenus — the recited funeral oration as imitation: Socrates performs Aspasia performing the ideal orator (representation at one remove); a referenced instance, not a developed treatment.