Editing Photios I of Constantinople (section)

== Writings ==
=== ''Bibliotheca'' ===
The most important of the works of Photius I is his ''[[Bibliotheca (Photius)|Bibliotheca]]'' or ''Myriobiblon'', a collection of extracts and abridgements of 280 volumes of previous authors (usually cited as Codices), the originals of which are now to a great extent lost. The work is especially rich in extracts from historical writers.{{sfn|Chisholm|1911|p=483}}

To Photius I, we are indebted for almost all we possess of [[Ctesias]], [[Memnon of Heraclea]], [[Conon (mythographer)|Conon]], the lost books of [[Diodorus Siculus]], and the lost writings of [[Arrian]]. Theology and ecclesiastical history are also very fully represented, but poetry and ancient philosophy are almost entirely ignored. It seems that he did not think it necessary to deal with those authors with whom every well-educated man would naturally be familiar. The literary criticisms, generally distinguished by keen and independent judgment, and the excerpts vary considerably in length. The numerous biographical notes are probably taken from the work of [[Hesychius of Miletus]].{{sfn|Chisholm|1911|p=483}}

Some older scholarship speculated that the ''Bibliotheca'' was compiled in [[Baghdad]] at the time of Photius's embassy to the [[Abbasid]] court since many of the mentioned works were rarely cited during the so-called Byzantine Dark Ages c. 630 – c. 800, and it was known that the Abbasids were interested in works of Greek science and philosophy.<ref>{{harvnb|Jokisch|2007|pp=365–386}}.</ref> However, specialists of this period of Byzantine history, such as [[Paul Lemerle]], have shown that Photius I could not have compiled his ''Bibliotheca'' in [[Baghdad]] because he clearly states in both his introduction and his postscript that when he learned of his appointment to the embassy, he sent his brother a summary of books that he read ''previously'', "since the time I learned how to understand and evaluate literature" i.e. since his youth.<ref>{{harvnb|Jokisch|2007|pp=365–386}}; {{harvnb|Lemerle|1986|p=40}}.</ref> Moreover, the Abbasids were interested only in Greek science, philosophy and medicine; they did not have Greek history, rhetoric, or other literary works translated; nor did they have Christian patristic writers translated.<ref>{{harvnb|Lemerle|1986|pp=26–27}}.</ref> Yet the majority of works in ''Bibliotheca'' are by Christian patristic authors, and most of the secular texts in ''Bibliotheca'' are histories, grammars or literary works, usually rhetoric, rather than science, medicine or philosophy. This further indicates that the majority of the works cannot have been read while Photius I was in the Abbasid empire.

=== Other works ===
The ''[[Lexicon]]'' (Λέξεων Συναγωγή), published later than the ''Bibliotheca'', was probably in the main the work of some of his pupils. It was intended as a book of reference to facilitate the reading of old classical and sacred authors, whose language and vocabulary were out of date. For a long time, the only manuscripts of the ''Lexicon'' were the ''Codex Galeanus'', which passed into the library of [[Trinity College, Cambridge]]{{sfn|Chisholm|1911|p=483}} and Berolinensis grace., 22 October, both of which were incomplete. But in 1959, Linos Politis of the [[Aristotle University of Thessaloniki|University of Thessaloniki]] discovered a complete manuscript, codex Zavordensis 95, in the Zavorda Monastery (Greek: Ζάβορδα) in [[Grevena]], Greece, where it still resides.<ref>"[https://www.roger-pearse.com/weblog/2011/01/15/the-lexicon-of-photius The Lexicon of Photius]" by Roger Pearse, 15 January 2011.</ref>

His most important theological work is the ''Amphilochia'', a collection of some 300 questions and answers on difficult points in Scripture, addressed to Amphilochius, archbishop of Cyzicus. Other similar works are his treatise in four books against the [[Manichaeism|Manichaeans]] and [[Paulicianism|Paulicians]], and his controversy with the Latins on the Procession of the [[Holy Spirit in Christianity|Holy Spirit]].{{sfn|Chisholm|1911|pp=483–484}} Photius also addressed a long letter of theological advice to the newly converted Boris I of Bulgaria. Numerous other ''Epistles'' also survive.

Photius I is also the writer of two "mirrors of princes", addressed to Boris-Michael of Bulgaria (Epistula 1, ed. Terzaghi) and to [[Leo VI the Wise]] (Admonitory Chapters of Basil I).<ref>{{harvnb|Paidas|2005|loc=passim}}.</ref>

Photius I's [[epitome]] of [[Philostorgius]]' ''Church History'' is the principal source for the work, which is now lost.

The first English translation, by Holy Transfiguration Monastery, of the "[[Mystagogy of the Holy Spirit]]" by Photius was published in 1983.<ref>{{Cite book |last=Photius |title=On the Mystagogy of the Holy Spirit |publisher=Studion Publishers |date=1983 |isbn=0-943670-00-4 |url=https://books.google.com/books?id=5tPYAAAAMAAJ}}</ref> Another translation was published in 1987 with a preface by [[Archimandrite]] (now [[Archbishop]]) Chrysostomos of [[Mount Etna|Etna]].<ref>{{Cite book |last=Photius |author2=Joseph P. Farrell |title=The Mystagogy of the Holy Spirit |publisher=Holy Cross Orthodox Press |date=1987 |isbn=0-916586-88-X |url=https://books.google.com/books?id=y8XYAAAAMAAJ}}</ref>