Glossary of Greek Terms in Plato
Plato wrote in fourth-century Greek, and a lot of his most important words don't translate cleanly. Arete isn't just "virtue." Logos isn't just "word." If you're reading the dialogues in English, knowing what the underlying Greek term actually means will sharpen your reading considerably.
Below are the terms that come up most often. Each definition is short, but the cross-references will take you to a fuller treatment on this site.
Anamnesis — ἀνάμνησις
Recollection. Plato's theory that what we call learning is really the soul's recovery of knowledge it possessed before birth. The classic demonstration is in the Meno, where Socrates leads an uneducated slave boy to a geometric truth by questioning alone.
Source: Meno 81d–86b; Phaedo 72e–77a.
Aporia — ἀπορία
Perplexity, impasse. The state Socrates aims to leave his interlocutors in: realising they did not, after all, know what they thought they knew. Aporia is uncomfortable but valuable — it is the condition for genuine inquiry.
See also the Socratic method.
Arete — ἀρετή
Excellence, virtue. Often translated "virtue," but the word is broader. The arete of a knife is being sharp; the arete of a horse is running well; the arete of a human being is whatever lets a human being live well. Plato's ethics is largely an inquiry into what human arete actually is.
See the four cardinal virtues for Plato's specific account.
Daimon — δαίμων
A spirit, a being between mortal and divine. Socrates famously had a "daimonion" — an inner divine sign that warned him against wrong action. In the Symposium, Eros is described as a daimon: not a god, but a great mediating power.
Dialectic — διαλεκτική
The art of reasoned argument. For Plato, dialectic is the highest form of inquiry, distinct from mere debate. It moves from hypothesis to hypothesis until it arrives at unconditional first principles. Reserved in the Republic for those who have already mastered mathematics.
Dikaiosyne — δικαιοσύνη
Justice, righteousness. The central topic of the Republic. For Plato, justice is not primarily a legal or social concept but the right ordering of the parts of the soul.
See Plato's Republic and the tripartite soul.
Doxa — δόξα
Opinion, belief. Contrasted with episteme (knowledge). Doxa can be true or false, but it is unstable; it doesn't survive being questioned. The shadows on the cave wall are the realm of doxa.
Eidos / Idea — εἶδος / ἰδέα
Form. The technical term for what English readers call "the Forms" or "the Ideas." Despite the modern English word "idea," for Plato an idea is not a thought in someone's mind but an objective, eternal, unchanging structure that particular things imitate.
See the Theory of Forms.
Elenchus — ἔλεγχος
Refutation, cross-examination. The technical name for the Socratic method. The procedure: get someone to define X, get them to agree to other claims, show that the definition contradicts those claims.
Episteme — ἐπιστήμη
Knowledge. The strict sense: stable, justified, true cognition. For Plato, episteme is reserved for the Forms; everything below them is at best doxa. Source of the modern word "epistemology."
Eros — ἔρως
Love, desire, longing. Not just sexual love (though it includes that). For Plato, eros is the soul's longing for what it lacks — ultimately, beauty itself. The driving force of the philosophical ascent.
See the Symposium.
Eudaimonia — εὐδαιμονία
Flourishing, well-being. Often translated "happiness," but eudaimonia is not a feeling. It is the objective condition of a human life that is going well as a human life. The aim of all Greek ethical philosophy is to identify what eudaimonia consists in.
The Good — τὸ ἀγαθόν
The Form of the Good. The highest of the Forms. Just as the sun makes the visible world visible, the Good makes the intelligible world intelligible. The ultimate object of philosophical inquiry.
Kalon — καλόν
Beautiful, fine, noble. A single Greek word covers what English splits between "beautiful" (aesthetic) and "noble" (moral). For Plato, the two are not really separate — what is genuinely beautiful is also good.
Logos — λόγος
Word, account, reason, argument. One of the most overworked words in Greek philosophy. In Plato it usually means a structured account — the kind of explanation that distinguishes knowledge from mere true opinion. To have a logos is to be able to give reasons.
Mimesis — μίμησις
Imitation, representation. A central concept in Plato's critique of poetry. Art imitates the visible world, which itself imitates the Forms; art is therefore "third from the truth." The ban on most poetry in the ideal city rests on this.
Source: Republic Book X.
Nous — νοῦς
Mind, intellect, intuitive understanding. The highest cognitive faculty in the soul. What grasps the Forms directly when it has been properly trained.
Phronesis — φρόνησις
Practical wisdom. The kind of wisdom that knows what to do in particular situations. Distinct from sophia (theoretical wisdom). Aristotle would later make this distinction central; Plato uses both terms more fluidly.
Polis — πόλις
City-state. Not just a city in the modern sense but a self-governing political community: Athens, Sparta, Corinth. The default unit of Greek political analysis. Plato's Republic is, literally translated, "concerning the polis."
Psyche — ψυχή
Soul. Not just the religious soul of later Christian thought but the principle of life and consciousness. For Plato, the psyche has parts and structure — it is the proper object of ethical attention.
See the tripartite soul.
Sophia — σοφία
Wisdom. The first of the four cardinal virtues. The virtue proper to the rational part of the soul. Source of the words "philosophy" (love of wisdom) and "sophist" (wise-guy).
See the cardinal virtues.
Sophrosyne — σωφροσύνη
Temperance, self-control, soundness of mind. One of the four cardinal virtues. The right relationship between the parts of the soul; the appetites obeying reason. Sometimes translated "moderation," which understates how comprehensive Plato means it.
Thymos — θυμός
Spirit, spiritedness. The middle part of the soul in Plato's tripartite model. The seat of anger, indignation, the love of honour, and shame. Naturally allied with reason if properly trained.
See the tripartite soul.
Techne — τέχνη
Craft, art, skill. A productive expertise that can be taught and that has a definite goal: medicine, navigation, shoemaking. Plato repeatedly uses techne as a model for what he wants ethics and politics to become — a real expertise rather than a matter of opinion.