The faith by which we live shall never vary in any age . . . for one is the faith which sanctifies the Just of all ages.
Pope Leo ITeach nothing new, but instill into all men's breasts those things which the Fathers of revered memory have with harmony of statement taught... Preach nothing else than what we received from our forefathers... Accordingly, both in the rule of faith and in the observance of discipline, let the standard of antiquity be maintained throughout.
Pope Leo IHe that sees another in error and endeavors not to correct it, testifies himself to be in error.
Pope Leo I