A theological development of profound importance to our study of the late Middle Ages is the introduction and development of the doctrine of papal infallibility.  The origins of the doctrine of papal infallibility in the years 1300 are a fascinating story, but the scope of this work will focus on the main points.Because some trace the origins of the doctrine of papal infallibility to canonists, these will be the starting point.  In the century between 1150 and 1250, a study of the writings of canonists and theologians reveals that "they did not know any magisterium conferred upon Peter by the power of the keys; that they believe that in matters of faith an ecumenical council was greater than the pope;that they did not hold that papal pronouncements were irreformable ex sese[in themselves] . "  As Tierney points out, "above all, canonists did not teach that the pope was infallible."  On the contrary, the position was generally supported contrasted the unfailing faith of the Church with the fallibility of individual popes. Theologians, who wrote much less on the subject, also shared this general point of view.
In 1254 a dispute arose between the mendicant friars and the secular masters at the University of Paris.  Both Dominicans and Franciscans were involved, but it is the Franciscans who require our attention. Their order had been granted privileges since 1230, and their dependence on these privileges would prove to be problematic. The problem came from his assertion that his doctrine of "apostolic poverty" was not simply a good way of life or a better way of life, but that it was an essential aspect of Christ's perfect form of life transmitted to the apostles.  Many of them claimed that St. Francis had been the first Christian to properly understand the gospel since the days of the apostles and that the Franciscans were the only members of the Church who truly led Christian lives.  Of course, these allegations were highly controversial and raised with little opposition. Bonaventure, the head of the Franciscan order, responded to arguments against order by developing a theory of poverty which he himself called "condescension." Without going into all the details, it is enough to say that in 1279, in the Bull exiit qui seminat , Pope Nicholas III gave papal sanction to the doctrine of Bonaventure and stated that "the Franciscan form of life really corresponds to the form of perfection that Christ taught the apostles ". 
The first great medieval Christian to affirm the doctrine of papal infallibility was Peter of John Olivi, a highly influential Franciscan in the decades after Bonaventure's death. He lived and wrote in a period of time in which the Franciscans were divided into two great camps: the greatest and least rigorous "Community" and the strict "spiritual" ones. Olivi himself was a prominent spokesman for the spiritual.  The reason why Olivi, unlike Bonaventura, developed the doctrine of papal infallibility, unlike his predecessor, was his constant fear of the possibility that a future pseudo-pope would seek to overthrow the true faith (ie the Franciscan way of life) . In Olivi's mind, it was necessary for the decrees of popes (such as Nicholas III) "to be regarded as not only authoritative for the present, but immutable, unreformable for all time."  This, however, was impossible within the framework of the doctrine of the papal sovereignty of the canonists. They understood that a doctrine of infallibility would limit the sovereignty of an individual pope. Olivi knew that much. His "new theory of papal infallibility was designed to limit the power of future popes, not to free them from any restraint." 
The new doctrine of Olivi was ignored for forty years, but in 1322 Pope John XXII revoked the pro-Franciscan provisions of the Exiit and issued a new statement on the doctrine of Christ's poverty.  The Franciscans were dismayed and reacted by issuing two encyclical letters defending their doctrine.Pope John answered at the end of 1322 in the bull Ad conditorem . For John, "the idea that any decisions should be incorrigible was presented ... simply with a threat to its own sovereign authority."  This bull elicited a passionate response from the Franciscans who appealed against it to the pope himself. In November 1323, Pope John XXII issued his final judgment on the issue of the poverty of Christ in the bull Cum internovulos . The bull refers to the view that "Jesus Christ and his apostles had nothing in common or in common" as erroneous and heretical.  Because this bull explicitly contradicts the old bullExiit , the Franciscans began to assert the incorrigibility of the former to the point of condemning John's view as heretical. As Tierney notes,
The first evident condemnation of a papal bull came from ... a group of Franciscan dissidents who found refuge at the court of the excommunicated emperor Louis IV of Bavaria. Their protest, included as a sort of digression in the Emperor's Appeal of Sachenhausen on May 24, 1324, not only defended the doctrine of evangelical poverty and denounced John XXII as a heretic for attacking doctrine, but also presented a new formulation of theory of papal infallibility. In this work, for the first time, the ancient teaching that one of the keys that had been delivered to Padro was the "key of knowledge" was used to support the doctrine that the pope was infallible when he used this key to define truths about faith and morality. It was a great theological breakthrough. 
The Sachenhausen Appeal brought the discussion to the domain of Catholic thought for the first time.
In November 1324, John XXII replied in the Bull Quia quorum that the "Father of lies" has led his [Pope's] enemies to defend the erroneous thesis that "what the Roman Pontiff once defines in matters of faith and morality with the knowledge is so immutable that it does not allow a successor to revoke it." 
The 1324 exchanges are of fascinating interest to a historian of the doctrine of papal infallibility. Here, for the first time, a doctrine of papal infallibility based upon the Petrine power of the keys was manifestly proposed. But the doctrine was for antipope father rebels and not theologians of the Curia. And far from embracing the doctrine, the Pope indignantly denounced it as a pernicious invention. 
The most striking thing about the doctrine of papal infallibility is that it "was invented almost fortuitously because of a historical concentration of unusual circumstances that gave rise to a doctrine useful to a particular group of contenders." 
There is no convincing evidence that papal infallibility constituted any part of the theological or canonical tradition of the Church before the thirteenth century; the doctrine was first created by a few Franciscan dissidents because it was convenient and convenient for them to invent it; eventually, but not only after much reluctance, it was accepted by the papacy because it suited the pope's convenience in accepting it. 
The Catholic doctrine of papal infallibility was not declared as official Catholic dogma until the first Vatican Council in 1870, but its origin can be traced to this obscure thirteenth-century battle between radical Franciscans and the papacy.
 For an excellent historical study of this issue, see Brian Tierney,Origins of Papal Infallibility: 1150-1350, (Leiden: EJ Brill, 1988).
 Canonists or canon lawyers were those who studied and systematized canonical laws - established church rules for practical purposes of order and discipline. Very often the canons of order and discipline were established in councils (such as Nicaea in 325 AD). But the collection and standardization of canon law reached its peak in the work of Gratian, whose decretum was the standard textbook throughout the late Middle Ages.
 Tierney, op. cit., 57.
 A "mendicant" is someone who depends on alms to live
 Cf. Latourette, op. cit., I: 429-436.
 Tierney, op. cit., 67-72.
 Ibid., 59-70.
 Ibid., 93-101.
 Ibid., 125.
 Ibid., 130.
 La Due, op. cit., 146-147.
 Tierney, op. cit., 178-179.
 Quoted in Tierney, op.cit., 178-179.
 Ibid., 182.
 Quoted in Tierney, op. cit., 186.
 Ibid., 187-188.
 Ibid., 274.
19] Ibid., 281.
From the book The Shape of Sola Scriptura by Keith A. Mathison, pp. 58-61
Excerpts originally taken from: