Although Antony was an Iconodule, he became an Iconoclast in 815, when Emperor Leo V the Armenian reinstituted Iconoclasm. The reason for Antony's change of heart is said to have included his hope for attaining the patriarchate.
Antony initially adhered to the iconophile viewpoint but later shifted towards iconoclasm in 815 when Emperor Leo V the Armenian re-established Iconoclasm. This shift may have been driven by Antony's ambition for a higher ecclesiastical office, such as the patriarchate.