St. Isidore: On Heresy

“THEREFORE, heresy is so called from the Greek word meaning ‘choice,’ by which each chooses according to his own will what he pleases to teach or believe. But we are not permitted to believe whatever we choose, nor to choose whatever someone else has believed. We have the apostles of God as authorities, who did not themselves of their own will choose what they would believe, but faithfully transmitted to the nations the teaching received from Christ. So, even if an angel from heaven should preach otherwise, he shall be called anathema.”

~St. Isidore of Seville (c. 560 – 636): Etymologies, 8, 3.

Statue of Isidore of Seville by José Alcoverro, 1892,
outside the Biblioteca Nacional de España, in Madrid.
(Photo credit: Luis García)