The derivation
For once the authorities do not part ways. μένος is among the firmest etymologies in the whole soul-vocabulary, and all three dictionaries land on the same verdict: it is an inherited Indo-European noun, identical with the Sanskrit and Avestan words for mind.
Frisk states the equation flatly: μένος is "als altes Verbalnomen mit aind. manas- n., aw. manah- n. 'Geist, Gedanke, Wille, Streben' identisch, idg. *menos n." — an old verbal noun identical with Sanskrit manas- and Avestan manah- "spirit, thought, will, striving," from Indo-European *menos (Frisk, GEW s.v. μένος). He extends the match across the compound system: Greek δυσ-μενής "ill-disposed" answers exactly to Avestan dus-manah- and Sanskrit dur-manas-, and εὐ-μενής "well-disposed" to Sanskrit su-manas-. He then sets a parallel formation beside it: Latin mens, -tis "mind" matches the Sanskrit t-stem, a different build on the same root — μένος is to mens as γένος is to a t-stem beside it (Frisk's reconstructed suffix is carried in garbled OCR and is left unreproduced here).
Beekes agrees and compresses the same history into a single line, deriving μένος from the root *men-s- 'mind' and pointing to μένω (Beekes, EDG s.v. μένος). The verb of remaining and the noun of force sit on the same Indo-European base of thinking, having in mind, being intent. The OCR of Beekes's etymology flag is garbled here; the legible content — the root and the cross-reference — is unambiguous.
Chantraine, who is less interested in the reconstruction than in the word's behavior, fixes the Greek sense precisely: μένος "se dit de l'esprit qui anime le corps, mais toujours comme principe actif" — it names the spirit that animates the body, but always as an active principle. It can mean intention, will, passion, ardor for battle, "la force qui anime les membres," the force that animates the limbs — and it is said of animals, of a spear, of fire, of rivers (Chantraine, DELG s.v. μένος). He notes the periphrastic idiom in which μένος works like βίη — "the might of the son of Atreus" standing for the mighty Atreid himself.
So the not-disagreeing is itself the finding. Where ψυχή and θυμός fracture the scholarship, μένος holds: a single Indo-European word for the engaged, outward-driving mind, surviving in Greek as raw animating force.
Root
- *men-(s)- "to think, have in mind" — accepted by all three: Beekes (*men-s- "mind," cf. μένω), Frisk and Chantraine (idg. *menos n.). Cognate row: Sanskrit manas-, Avestan manah- "spirit, thought, will"; the compound pairs δυσ-μενής : dus-manah- / dur-manas- and εὐ-μενής : su-manas-; Latin mens as a parallel *mn-ti- build.
- No competing root is offered. The disagreement, where the dictionaries flag one, is internal to the derivative verbs (μενεαίνω, μενοινάω), not to μένος itself.
In the corpus
236 occurrences in the corpus. μένος belongs to the active register: not the breath that leaves at death (ψυχή) nor the seat of feeling (θυμός), but the force that pours into those seats and drives them. The Homeric texture, which the count rests on, shows μένος as something poured, cast, or increased — a quantity of animating energy that a god can put in and wine can restore. Its Indo-European pedigree means the word arrives in Greek already old: the same *menos that Vedic singers used for the engaged mind, redeployed by the epic for the surge that fills the limbs before a charge.
The word's world
In the tragic and epic body, μένος is a fluid that fills the inner organs. Ruth Padel maps it exactly: "When Agamemnon is angry, his 'black phrenes fill around greedy with menos.' Menos fills phrenes, soul, and thumos. The menos of thumos 'boils,' like choli… Menos 'seizes' and fills thumos," yet it "can also more generally mean 'energy' — wine 'increases menos in a weary man'" (Padel, In and Out of the Mind). Its relationship to θυμός is, in her word, "mobile and inconsistent": each can act on the other. Bruno Snell finds the same in the god-sent variety — when Apollo "cast strength in [Glaucus's] thymos," the divine gift "has nothing supernatural about it"; it is the ordinary collecting of force under pressure (Snell, The Discovery of the Mind). μένος is the soul-vocabulary's word for that collectible, pourable, depletable charge of life.
Authorities: Beekes, Etymological Dictionary of Greek (Brill 2010) s.v. μένος (scan pp. 981–982, #4018); Chantraine, Dictionnaire étymologique de la langue grecque s.v. μένος (scan p. 702, #5200); Frisk, Griechisches etymologisches Wörterbuch s.v. μένος (scan p. 1180, #3821; Nachträge pp. 2277–2278, #7636 — pointing to R. Schmitt on the μένος = Sanskrit manas equation, and Adkins JHS 89 (1969) on μενεαίνω). Interpretive sources retrieved from the Oracle library (Classical Philology & Ancient Thought): Padel, In and Out of the Mind (1994); Snell, The Discovery of the Mind (1953); cf. Bremmer, The Early Greek Concept of the Soul (1983). Scholarly anchors named by the dictionaries: Snell, Entdeckung des Geistes 35; R. Schmitt, Dichtung und Dichtersprache 181–194; Latacz, Wortfeld der Freude 23. Corpus figures: Logoi corpus, live. Receipt: soul-word-journey-v0.