By Pauper Peregrinus

Since the days of the apostles, the Church has had two kinds of law. There is divine law, which she has received from God, and which, expounding for all mankind, she may never change. And there is canon law, which she enacts or retracts on her own authority, the better to govern her children. The former is found when the apostles taught the converted gentiles to abstain from drunkenness; the latter, when they decided that the gentiles should abstain from food with blood in it, so as to promote table-fellowship between Jewish and Gentile believers, in those early years.

After the apostles had gone to their reward, popes, bishops and councils continued to enact laws for the good ordering of the faithful. Thus, the great Council of Nicaea in 325 not only defined the consubstantiality of the Son with the Father, but also laid down that a priest must have no woman other than a mother, sister or aunt living in his house, and that Catholics who had spontaneously sacrificed to idols during the Great Persecution must wait twelve years before receiving Holy Communion again.

As the centuries passed, the laws multiplied. Sometimes their meaning would be doubtful; sometimes, one law might seem to contradict another. By the twelfth century, the time had come to sort out the confusion. Among those who undertook this work, the most famous is an Italian scholar called Gratian (not to be confused with a Roman emperor of the same name), who lived from around 1100 to 1159, and who is reckoned “the Father of Canon Law.” Little is known of his life, but he taught at Bologna, where he composed a work called A harmony of discordant canons; it has come to be generally if rather inaccurately called the Decretum, or “decree.” It cites thousands of official texts, and arranges them in a logical order that starts from general principles and moves on to particular questions. Gratian also commented on much of what he quoted. His book proved so useful that it was adopted by everyone. In this way was born canon law as a subject distinct from theology.

Those who commented on Gratian’s work during the 12th and early 13th centuries are known as the “decretists.” Among the many topics that they debated, one of perennial interest is the problem of the “heretical pope.” This problem arises when we combine two propositions on which all the decretists were agreed: that the occupant of the see of Rome is not subject to legal judgment by human beings, and that it is possible that a pope may be or become a heretic. The problem is complicated by the fact that both divine law and canon law are in play: divine law, since God will presumably have revealed to us the principles to follow in such an emergency, and canon law, since the manner in which popes are chosen is something that can vary over time.

Interestingly, we don’t find a discussion of this question in the great theologians of the period. Peter Lombard, a French contemporary of Gratian who performed for theology a service similar to that done by the Italian for canon law, did not mention the problem in his own famous text-book, The Sentences. This explains why we find no discussion of it in the great 13th century theologians, such as St. Albert, St. Bonaventure, and St. Thomas.

In any case, Gratian placed the question on the table by inserting into his Decretum a letter sent about a century earlier by Pope Leo IX to Michael Cerularius, a wayward patriarch of Constantinople. Having first set forth the pre-eminence and duties of the bishop of Rome, the letter continued: “No mortal presumes to rebuke him, since the one who is to judge all men is himself to be judged by no one, unless perhaps he should be found straying from the faith.”

Although Gratian himself did not offer any commentary on this memorable saying, his successors were not so reticent. They all understood it to refer to a sitting pope, not to one who had already died. Two main schools of thought came into being. The first school is associated with a certain Huguccio of Pisa, whose Summa, written around 1190, is reckoned by historians as the greatest of the decretists’ works. He distinguished between a pope who was rejecting some dogma that the Church had already defined and one who was trying to introduce into the Church some new idea, that some people considered heretical. The latter hypothesis would be realized more than a century later, when Pope John XXII began to put it about that the souls of the just did not enjoy the vision of God until the end of the world. In such a case, said Huguccio, the objectors should not be allowed to put the pope on trial for heresy: the first see is judged by none.

But if the former hypothesis were realized, things would be different. Suppose (which God forbid) a pope were to come onto the balcony of St. Peter’s and say: “There was a time when the Son was not; he is not God in the same sense as the Father.” If it were to prove on investigation that he was not joking or intoxicated or speaking under grave duress, then, says Huguccio, the cardinals must condemn him for heresy and elect a successor. To the objection that they would be judging their legal superior, which is impossible, he replies that in these circumstances, the pope would “no longer be a superior, but would be inferior to every Catholic.” In modern parlance, we would say that such a pontiff had excommunicated himself ipso facto. Pope Innocent III, who originally studied under Huguccio, appears to have shared this opinion, to judge from sermons that he preached for the anniversary of his consecration.

In fact, Huguccio didn’t limit himself to a case of blatant heresy. For him, any crime committed by a pope would cause him to lose the papacy if it were sufficiently grave and sufficiently notorious. “Is it not like committing heresy to scandalize the Church?” he asks rhetorically. He gives the examples of simony, concubinage, and other things that I cannot mention in a family magazine.

The other school of thought was represented by an English canon lawyer, who was called, after the simple fashion of those days, “Alan the Englishman” (Alanus Anglicus). Writing around 1210, Alan argued that in determining matters of faith, a pope possesses less authority than a council of bishops or even than the college of cardinals, and hence that either body may try a pope on a question of heresy, even if it concerns a point of doctrine not previously defined, and that it may depose him if guilty. But on all other matters, Alan declared, a pope is superior to a council. He concluded that neither bishops nor cardinals could depose a pope for any crime save one against the faith. And Alan’s school of thought apparently proved more popular among canon lawyers in the later Middle Ages.

Someone might wonder: how did these two schools deal with the doctrine of papal infallibility? The simple answer is that they did not. Catholics in the 13th century were aware, at least implicitly, that God would not allow the pope to err when defining a dogma: hence St. Thomas Aquinas states that it pertains to the Roman pontiff to pronounce judgment about matters of divine revelation, “so that they may be held by everyone with unshaken faith.” But the question of papal infallibility had hardly yet become the object of systematic investigation. Hence, the canon lawyers of the time did not think to explain that even if a pope were a heretic, God would prevent him from proclaiming his heresy as dogma, and making acceptance of it a condition of communion.

As Aristotle remarks, none of the arts or sciences is perfect from the beginning, and this applies also to canon law. Neither Huguccio nor Alan the Englishman saw all the truth about this difficult question. Today, canon lawyers would agree with Huguccio that a pope loses his office automatically for professing what is manifestly heresy, though they would add that it must be an unambiguous statement, not something done by nods and winks. But they would not agree with him in extending this to other crimes; with Alan Anglicus they would say that there is something special about heresy. Only heresy (and schism) make a man to be “less than any Catholic.” Yet they would not agree with Alan’s idea that anyone deposes a heretical pope; at most, it may recognize his self-deposition. Nor would a council have the right by itself, as he supposed, to define some disputed question that the Church had not previously resolved.

Much more might be said about this question, of course. But perhaps this is enough to suggest what fascinating discussions may be found in dusty tomes of canon law, or in the forgotten manuscripts of the Middle Ages.