SVF I.205

Original — Ancient Greek

ἔστι δὲ αὐτὸ τὸ πάθος κατὰ Ζήνωνα ἡ ἄλογος καὶ παρὰ φύσιν ψυχῆς κίνησις ἢ ὁρμὴ πλεονάζουσα.

StoicOs Translation

Passion itself is, according to Zeno, an irrational movement of the soul contrary to nature — or an excessive impulse.

Context

Diogenes Laërtius compiled his Lives around five centuries after Zeno, drawing on earlier handbooks. His summary of Stoic ethics preserves many school definitions with name-tags; here he marks this one explicitly as Zeno's (κατὰ Ζήνωνα). The witness is neutral and compilatory rather than critical.

Source notes:Greek text as transmitted in Diogenes Laërtius 7.110 (= H. von Arnim, SVF I, no. 205). Diogenes explicitly attributes the definition to Zeno (κατὰ Ζήνωνα) within his doxographic summary of Stoic ethics.

What the source actually tells us

This testimony reports Zeno's definition of pathos in two formulations: an irrational, unnatural movement of the soul, or an excessive impulse (ὁρμὴ πλεονάζουσα). Whether both formulations are Zeno's own or the second reflects later school usage cannot be determined with certainty from this witness.

Philosophical meaning

This is the root of the entire Stoic therapy of the emotions: a pathos is not a raw feeling but a movement of the soul that has escaped reason — an impulse that overshoots. Emotion is thus something the soul does, not merely something it suffers, which is why the Stoics believed it could be trained.

Practical wisdom

If a passion is an impulse that overshoots, the practical work is not to feel nothing but to notice the overshoot: the moment a reaction outruns your judgment. Zeno's definition turns emotional life from something that happens to you into something you can examine.

Go deeper

• Train it: Stoic Training Part 2 — Emotions →
• Study the passions in Stoic Ethics →