A Greek philosopher, born at Soli, in Cilicia, and lived in Athens; specially skilled in dialectic; the last and greatest expounder and defender of the philosophy of the Stoa, so pre-eminent, that it was said of him, "If Chrysippus were not, the Stoa were not"; is said to have written 705 books, not one of which, however, has come down to us save a few fragments (280-208 B.C.). See Stoicism.