St. Theodore the Studite—Studium
(759-826 A.D.):
“If anyone should not number with the
other heresies the heresy which attacks the holy icons (since it alienates its followers
from God as much as the others do), but should say that communion with heretics
is a matter of indifference, he is a heretic.” (“First Refutation of the
Iconoclasts,” PG
99:352B, in William J. DeTucci, Communicatio in Sacris: The Roman
Catholic Church Against Intercommunion with Non-Catholics [rev ed.; 2012], 131)
Further Reading:
Answering Fundamentalist Protestants and Roman Catholic/Eastern Orthodox on Images/Icons