These words I, Leo, have set down for love and as a safeguard of the orthodox faith (Haec Leo posui amore et cautela fidei orthodoxa). - Pope Leo III (defending the original Creed by engraving it in silver to display in Rome)

These men have said all the rash impudence there is to say... - Patriarch St. Photius the Great (Mystagogy of the Holy Spirit)

"The Symbol of the Faith must be preserved inviolate, as at its origin. Since all the holy doctors of the Church, all the Councils and all the Scriptures put us on our guard against heterodoxy, how dare I, in spite of these authorities, follow those who urge us to unity in a deceitful semblance of union—those who have corrupted the holy and divine Symbol of Faith and brought in the Son as second cause of the Holy Spirit" - St. Mark of Ephesus - The Pillar of Orthodoxy

"The Latins are not only schismatics but heretics... we did not separate from them for any other reason other than the fact that they are heretics. This is precisely why we must not unite with them unless they dismiss the addition from the Creed filioque and confess the Creed as we do." - St. Mark of Ephesus - The Pillar of Orthodoxy

"It is impossible to recall peace without dissolving the cause of the schism—the primacy of the Pope exalting himself equal to God." - St. Mark of Ephesus - The Pillar of Orthodoxy

"We seek and we pray for our return to that time when, being united, we spoke the same things and there was no schism between us." - St. Mark of Ephesus - The Pillar of Orthodoxy

 

"The filioque is the outward, efficacious, and visible symbol of an inward and metaphysical depravity." - Dr. Joseph P. Farrell