The consensus of the Church over time defines its catholicity—that which is believed at all times by the entire Church. St. Vincent of Lerins, wrote in his "Commonitoria" (434 AD), that Church doctrine, like the human body, develops over time while still keeping its original identity: "n the Orthodox Church itself, all possible care must be taken, that we hold that faith which has been believed everywhere, always, by all" Those who disagree with that consensus are not accepted as authentic "Fathers." All theological concepts must be in agreement with that consensus. Even those considered to be authentic "Fathers" may have some theological opinions that are not universally shared, but are not thereby considered heretical. Some Holy Fathers have even made statements that were later defined as heretical, but their mistakes do not exclude them from position of authority (heresy is a sin of pride; unintended error does not make one a heretic, only the refusal to accept a dogma which has been defined by the church). Thus an Eastern Orthodox Christian is not bound to agree with every opinion of every Father, but rather with the consensus of the Fathers, and then only on those matters about which the church is dogmatic.