Question: What is an "anti-pope? Aren't the Vatican II Popes really antipopes?
Answer: The Catholic Encyclopedia and Donald Attwater's Catholic Dictionary offer substantially the same definition for "antipope" -- "a false claimant of the Holy See in opposition to a pontiff canonically elected." Historical records are not always perfectly clear, but scholars generally enumerate about thirty antipopes, the list usually beginning with Hippolytus in the early third century, and ending with Felix V in 1449. Dom Guéranger holds that an unnamed antipope predated Hippolytus, and wrote a tract (called the Philosophumena) against the true Pope.
Modern people think of a papal election as a well behaved meeting of the College of Cardinals, acting with a fair degree of unanimity, conducting several ballots each day until a puff of white smoke from their chimney announces the election of one whom they all can generally support.
This like-minded sense of purpose was often lacking in selecting Popes during the thousand or so year period extending very roughly from 500 to 1500 A.D. The "renaissance" and its accompanying rise in secular government caused papal electors to remember what their predecessors knew during Roman persecutions and Barbarian invasions; that it is "us against them" and that we are foolish to quarrel amongst ourselves, thereby giving an advantage to the secular powers.
But, during that middle period -- when the Church held real political power -- papal elections were often a "poower play" involving an emperor or two, several kings and lesser nobles, the Roman senate, the papal curia, the College of Cardinals, the influential families of Europe, and sometimes even those who had the actual right to elect a Pope, the Faithful who lived in Rome. Thus, a papal election became something of a "contest" -- something to be "won" by the party with the best strategy and greatest advantages. Like an American Presidential debate, such contests sometimes ended with both sides proclaiming themselves "victors." To compound matters, the parties concerned did not always wait until the reigning Pope died of natural causes before forcing a new election -- sometimes, the responsible electors were made to act under threat of mob violence -- and, sometimes the electors ignored the election rules currently in force. History is written by the winners, so it is occasionally difficult to judge which side actually lost, and who is, therefore, the antipope. Some Popes who seem to have been elected in an irregular fashion were, nonetheless, accepted as legitimate; legitimacy seeming to depend more on acceptance than election.
For example, Clement II (1046) was nominated by Emperor Henry III and elected Pope after Henry's soldiers deposed Benedict IX, Gregory VI, and Silvester III, all of whom claimed simultaneously to be Pope. Clement is counted among the legitimate Popes, as is Benedict, who returned to being Pope after Clement's death!
Urban VI (1378) was elected under threats of violence by the Roman mobs, tired of having French Popes resident at Avignon. Several weeks later, the Cardinals repudiated Urban and elected Clement VII, a Swiss who moved back to Avignon, thereby initiating the Western Schism.
Gregory VII (1073) was elected by popular acclamation, even though the rules of Nicholas II and the Lateran Council, then in force, reserved election to the Cardinal Bishops.
For lack of a more precise term "antipope" is used a trifle loosely when the Holy See is vacant during a brief part of the usurper's claim. The antipope Eulalius (418-419) was elected by a faction of the clergy on the day before a larger faction elected Pope Boniface I (418-422), and the claim of the antipope Hippolytus spanned the pontificates of three Popes; but no one suggests that Eulalius and Hippolytus were anything other than antipopes during the times of the vacancies.
It should also be noted that the Avignon "popes" of the Western Schism are often referred to by a kinder term than "antipope." Titles like "Pope within the realm of his obedience" are employed because of the complexity of the situation and the good faith in which many supported the French "popes."
Implicit in the question asked by our reader is the possibility that a reigning Pope might become an antipope by espousing or condoning heresy. For this to happen, the heretical Pope would first have to be removed by the Church and a replacement Pope canonically elected -- only then would the heretic be an antipope, and only if he insisted that he was still Pope. Over the centuries most canonists have agreed that a Pope can be removed, in theory, for heresy, but they have disagreed over the exact manner in which such a Pope might be removed in fact. Some, like Hostensius, hold that the Cardinals or the Curia are competent; others required an Ecumenical Council; while still others insisted that no man could judge the Pope and that his actions could be weighed only in the retrospect of history by future generations.
To be a heretic in the legal sense of that term requires public adherence to serious error even after receiving an official warning from one's superior. In the case of a bishop (and, a fortiori, the Pope), the laws of the Church do not apply automatically, but must be brought to bear through due process. In the case of an heretical Pope, it is not at all clear as to who might warn him to abandon his errors, or who is competent to conduct a legal process against him. Such things are never supposed to have to happen, and until the 1960s, could be presumed to be self healing when the heretic died and clearer heads could be counted upon to prevail.
St. Marcellinus 296-304, Liberius 352-366, Anastasius II (496-498), Honorious I 625-638, John XXII 1316-1334 are among those enumerated by Church historians as holding, sympathizing with, or being reluctant to criticize heretical notions. The Third Council of Constantinople posthumously rebuked Honorious for his association with Monothelitism -- and it is possible that Liberius had a coadjutor bishop appointed for him in the Roman See in the person of Felix II. Anastasius II's death averted an almost certain schism. John XXII retracted his error only on his deathbed. But the Church removed none of these Popes, and none are among those reckoned as antipopes.
And, just as some Popes failed the Church in matters of faith, others failed in matters of morals; John XII, for example, or Alexander VI (Borgia). But, again, none of these men are reputed as antipopes.
One may not like the run of Popes since Vatican II. They may be imprudent, and altogether too frequently they may be an embarrassment with their laxity of doctrine and superfluous apologies for everything the Church has ever done, perhaps even heretical -- but, at least for the present, the incumbent is not an antipope.