Chrysippus of Soli (Cilicia) came to Athens and became the pupil of Cleanthes, the second scholarch of the Stoa; according to Diogenes Laertius (VII 179–184) he also attended the Academics — and so knew his opponents' arguments better than they did. After Cleanthes' death (c. 230 BCE) he headed the school and led it until his own death. His productivity was phenomenal: over 705 books (DL VII 180) — he wrote five hundred lines a day, quoting other texts copiously. Not a single complete work survives: Chrysippus reaches us as a colossal scatter of fragments and paraphrases (the greater part of vols. II–III of von Arnim's SVF is his).

The ancient formula of his significance is DL VII 183: εἰ μὴ γὰρ ἦν Χρύσιππος, οὐκ ἂν ἦν στοά — "had there been no Chrysippus, there would be no Stoa."

If Zeno gave the Stoa its theses, Chrysippus gave it system and defence. His contribution defined the school in all three parts of philosophy:

• Logic. The creator of propositional logic (twenty-three centuries before its "rediscovery"): the doctrine of the λεκτόν (the sayable), of conditional and disjunctive propositions, the five "indemonstrable" moods of inference. Antiquity said: "if the gods had dialectic, it would be the dialectic of Chrysippus" (DL VII 180).
• Physics. The systematization of the doctrine of pneuma, of causality and fate as an unbroken chain of causes; classical compatibilism — the famous image of the cylinder that rolls when pushed, but according to its own shape (apud Cic. De fato 41–43): fate supplies the occasion, character determines the response.
• Ethics. The rigorous formalization of the doctrine of the passions as judgments (κρίσεις), of the end as life according to the experience of natural events, of the fitting and the right act. Through Chrysippus's "therapy of judgments" runs the straight road to Epictetus and Marcus.

For Marcus, Chrysippus is not an interlocutor but a foundation: nearly every doctrine the Meditations rests on (passions as judgments, fate as causality, the sympathy of the whole, the theodicy of partial evil) belongs in its technical form to Chrysippus, even where his name goes unmentioned.

• 06-42 — Marcus recalls Chrysippus's image of the comic verse: even a "mean and ridiculous verse" in a play is needed by the work as a whole — so too the fault-finders and resisters find their place in the design of the cosmos (the comparison is preserved in Plutarch, De comm. not. 1065d = SVF II 1181). Characteristically, Chrysippus is invoked as the author of the theodicy of partial evil.
• 07-19 — "how many Chrysippuses … has eternity already swallowed": the name in the plural, as a generic, in the roll-call of the greatest minds (Chrysippus, Socrates, Epictetus) gulped down by the torrent of time. The passage's irony: eternity swallowed the very man who described its cycles.

• Diogenes Laertius VII 179–202 — biography, catalogue of works
• SVF II–III (H. von Arnim) — the principal corpus of fragments
• LS (Long–Sedley, The Hellenistic Philosophers) — fragments with commentary, passim
• J. B. Gould, The Philosophy of Chrysippus, Leiden 1970
• T. Tieleman, Chrysippus' On Affections, Leiden 2003
• S. Bobzien, Determinism and Freedom in Stoic Philosophy, Oxford 1998 (Chrysippus's compatibilism)