The author of the Theologia mystica and the other works ascribed to the Areopagite proceeds, therefore, to develop the doctrines of Proclus with very little modification into a system of esoteric Christianity.
Religious thought about the angels during the middle ages was much influenced by the theory of the angelic hierarchy set forth in the De Hierarchia Celesti, written in the 5th century in the name of Dionysius the Areopagite and passing for his.
The last book (xvii.) treats of theology or (as we should now say) mythology, and winds up with an account of the Holy Scriptures and of the Fathers, from Ignatius and Dionysius the Areopagite to Jerome and Gregory the Great, and even of later writers from 'Isidore and Bede, through Alcuin, Lanfranc and Anselm, down to Bernard of Clairvaux and the brethren of St Victor.
When this historical heresy led to the inevitable persecution, Abelard wrote a letter to the abbot Adam in which he preferred to the authority of Bede that of Eusebius' Historia Ecclesiastica and St Jerome, according to whom Dionysius, bishop of Corinth, was distinct from Dionysius the Areopagite, bishop of Athens and founder of the abbey, though, in deference to Bede, he suggested that the Areopagite might also have been bishop of Corinth.
An essay in which he denies the identity of St Denis of Paris and St Denis the Areopagite (1641), caused a very lively controversy from which his opinion came out victorious.
That he had a competent acquaintance with Greek is manifest from his translations of Dionysius the Areopagite and of Maximus, from the manner in which he refers to Aristotle, and from his evident familiarity with Neoplatonist writers and the fathers of the early church.
Hilduin, abbot of St-Denis in the first half of the 9th century, identified Denis of Paris with Denis (Dionysius) the Areopagite (mentioned in Acts xviii.
Quasi jocando, he cited Bede to prove that Dionysius the Areopagite had been bishop of Corinth, while they relied upon the statement of the abbot Hilduin that he had been bishop of Athens.
Erigena's next work was a Latin translation of Dionysius the Areopagite (see Dionysius Areopagiticus) undertaken at the request of Charles the Bald.