Editing Photios I of Constantinople (section)

=== 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a book of reference to facilitate the reading of old classical and sacred authors, whose language and vocabulary were out of date.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>