Cleanthes is said to have held that all survive to the great conflagration which closes the cycle, Chrysippus that only the wise will.
Like the earlier Stoics, Cleanthes and Chrysippus, he held that virtue may be taught.
On this account he was accused of impiety by the Stoic Cleanthes, just as Galileo, in later years, was attacked by the theologians.
The grammar of the Stoics, gradually elaborated by Zeno, Cleanthes and Chrysippus, supplied a terminology which, in words such as " genitive," " accusative " and " aorist," has become a permanent part of the grammarian's vocabulary; and the study of this grammar found its earliest home in Pergamum.
He took the doctrines of Zeno and Cleanthes and crystallized them into a definite system; he further defended them against the attacks of the Academy.