He was industrious beyond all other men; as is plain from his writings; for he wrote more than seven hundred and five books. And he often wrote several books on the same subject, wishing to put down everything that occurred to him; and constantly correcting his previous assertions, and using a great abundance of testimonies. So that, as in one of his writings he had quoted very nearly the whole of the Medea of Euripides, and some one had his book in his hands; this latter, when he was asked what he had got there, made answer, "The Medea of Chrysippus." And Apollodorus. the Athenian, in his Collection of Dogmas, wishing to assert that what Epicurus had written out of his own head, and without any quotations to support his arguments, was a great deal more than all the books of Chrysippus, speaks thus (I give his exact words). "For if any one were to take away from the books of Chrysippus all the passages which he quotes from other authors, his paper would be left empty."
These are the words of Apollodorus; but the old woman. who lived with him, as Diocles reports, used to say that he wrote five hundred lines every day.
Chrysippus was the great Stoic logician; unfortunately we have only very indirect information about what he wrote on the subject. But if Diogenes Laertius is right (he may not be; his reliability is very uneven), most of Chrysippus's writings might not be very interesting.