When young, Arrian was the pupil and friend of Epictetus, who had probably withdrawn to Nicopolis, when Domitian expelled all philosophers from Rome. He took verbatim notes of his teacher's lectures, which he subsequently published under the title of _The Dissertations_ ([Greek: Diatribai]), in eight books, of which the first four are extant and constitute the chief authority for Stoic ethics, and _The Encheiridion_ (i.e. Manual) _of Epictetus_, a handbook of moral philosophy, for many years a favourite instruction book with both Christians and pagans. It was adapted for Christian use by St Nilus of Constantinople (5th century), and Simplicius (about 550) wrote a commentary on it which we still possess. The most important of Arrian's original works is his _Anabasis of Alexander_, in seven books, containing the history of Alexander the Great from his accession to his death. Arrian's chief authorities were, as he tells us, Aristobulus of Cassandreia and Ptolemy, son of Lagus (afterwards king of Egypt), who both accompanied Alexander on his campaigns. In spite of a too indulgent view of his hero's defects, and some over-credulity, Arrian's is the most complete and trustworthy account of Alexander that we possess. Other extant works of Arrian are: _Indica_, a description of India in the Ionic dialect, including the voyage of Nearchus, intended as a supplement to the _Anabasis; Acies Contra Alanos_, a fragment of importance for the knowledge of Roman military affairs; _Periplus of the Euxine_, an official account written (131) for the emperor Hadrian; _Tactica_, attributed by some to Aelianus, who wrote in the reign of Trajan; _Cynegeticus_, a treatise on the chase, supplementing Xenophon's work on the same subject; the _Periplus of the Erythraean Sea_, attributed to him, is by a later compiler. Amongst his lost works may be mentioned: [Greek: Ta mer Alexandron], a history of the period succeeding Alexander, of which an epitome is preserved in Photius; histories of Bithynia, the Alani and the Parthian wars under Trajan; the lives of Timoleon of Syracuse, Dion of Syracuse and a famous brigand named Timoleon. Arrian's style is simple, lucid and manly; but his language, though pure, presents some peculiarities. He was called "Xenophon the younger" from his imitation of that writer, and he even speaks of himself as Xenophon.