SVF I.206
Stoic: Zeno of Citium · Ancient source: Stobaeus, Eclogae, Book II — II 7,1 p. 39,5 W. · Source language: Ancient Greek · Source status: Direct quotation, Testimonium
Original — Ancient Greek
ὡς δ᾽ ὁ Στωικὸς ὡρίσατο Ζήνων· “πάθος ἐστὶν ὁρμὴ πλεονάζουσα.” οὐ λέγει “πεφυκυῖα πλεονάζειν”, ἀλλ᾽ ἤδη ἐν πλεονασμῷ οὖσα· οὐ γὰρ δυνάμει, μᾶλλον δ᾽ ἐνεργείᾳ. ὡρίσατο δὲ κἀκείνως· “πάθος ἐστὶ πτοία ψυχῆς”, ἀπὸ τῆς τῶν πτηνῶν φορᾶς τὸ εὐκίνητον τοῦ παθητικοῦ παρεικάσας.
StoicOs Translation
As the Stoic Zeno defined it: “Passion is an impulse in excess.” He does not say “naturally apt to exceed”, but already in a state of excess: not potentially, but actually. And he defined it in that other way too: “Passion is a fluttering (ptoia) of the soul” — likening the excitability of the passionate to the flight of winged creatures.
Context
In the prologue of Stobaeus' ethical anthology, an excerptor explains the Stoic definitions of passion and pauses over Zeno's precise wording — even correcting a possible misreading: the excess is actual, not merely potential.
Text verified against von Arnim, SVF I (1903), no. 206, pp. 50–51 (OCR of the scanned edition). Both definitions are given as quotations of “the Stoic Zeno”; the explanatory sentences between them (“he does not say…”) are the excerptor's exegesis. Von Arnim compares Stobaeus II 7,10 p. 88,11 for the ptoia formula.
What the source actually tells us
Two definitions quoted under Zeno's own name, with the excerptor's grammatical commentary presupposing a fixed transmitted wording. The first (“impulse in excess”) is confirmed by Diogenes Laërtius and Cicero (SVF I.205); the second, the ptoia-image, is preserved almost solely here.
Philosophical meaning
Impulse itself is healthy — nature moves every creature toward what is its own. Passion begins where impulse outruns the reason that should measure it: not a different faculty, but the same movement grown too strong. The second definition adds the phenomenology: the soul in passion flutters like a startled bird — quick, uncontrolled, no longer resting on judgment. Together they define disorder as excess, and calm as measure, not apathy of stone.
Scholarly uncertainty
The two definitions are presented as Zeno's fixed wording, but they reach us through an anonymous excerptor in Stobaeus, centuries later; the interpretive sentences between the quotations are certainly his, not Zeno's. The bird-comparison explaining ptoia may likewise be the excerptor's gloss on Zeno's one-word image.
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About this edition
StoicOs Ancient Library is a developing multilingual digital study edition of surviving early Stoic material. The Stoicorum Veterum Fragmenta assembled by Hans von Arnim provides the traditional reference framework. StoicOs distinguishes carefully between fragments, testimonia, later reports and interpretation. StoicOs translations are prepared from the surviving ancient-language sources where available.