Chrysippus, c.280-c.207 B.C., Greek Stoic philosopher, b. Soli, Cilicia. He was a disciple of Cleanthes and succeeded him as head of the Academy in Athens. After Zeno, the founder of Stoicism, Chrysippus is considered the most eminent of the school. He systematized Stoicism and reconciled the factions that threatened to split the school. Chrysippus wrote with exquisite logic but also gave great weight to prophecy and the irrational. Only fragments of his work survive.