T. W. Rolleston 
The Teachings of Epictetus 

But for the zeal and ability of one disciple we should not now possess any trustworthy account of the teaching of Epictetus. For, like not a few other sages, he wrote nothing – his teaching was purely oral, delivered, in the form of lectures or discourses, to the students who came to him to receive their education in philosophy. One of these students was Flavius Arrianus, afterwards Senator and Consul of Rome, named by Lucian ‘one among the first of Roman men, ‘ and known to us chiefly as author of the best history of Alexander the Great which was produced in antiquity. That history is still extant, but posterity owes Arrian still more abundant thanks for the copious notes of the teaching of Epictetus which he took down from his master’s lips in Nicopolis.