Pierre d'Ailly (;

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

''Petrus Aliacensis'', ''Petrus de Alliaco''; 13519 August 1420) was a French

theologian Theology is the systematic study of the nature of the divine and, more broadly, of religious belief. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of analyzing the ...

astrologer Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Dif ...

and

cardinal Cardinal or The Cardinal may refer to: Animals * Cardinal (bird) or Cardinalidae, a family of North and South American birds **''Cardinalis'', genus of cardinal in the family Cardinalidae **''Cardinalis cardinalis'', or northern cardinal, the ...

of the

Roman Catholic Church The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...

Academic career

D'Ailly was born in

Compiègne Compiègne (; pcd, Compiène) is a commune in the Oise department in northern France. It is located on the river Oise. Its inhabitants are called ''Compiégnois''. Administration Compiègne is the seat of two cantons: * Compiègne-1 (with 19 c ...

in 1350 or 1351 of a prosperous bourgeois family. He studied in Paris at the

Collège de Navarre The College of Navarre (french: Collège de Navarre) was one of the colleges of the historic University of Paris, rivaling the Sorbonne and renowned for its library. History It was founded by Queen Joan I of Navarre in 1305, who provided for thr ...

, receiving the licentiate in arts in 1367 and the master’s a year later, and was active in university affairs by 1372. D'Ailly taught the Bible in 1375 and the ''Sentences'' of

Peter Lombard Peter Lombard (also Peter the Lombard, Pierre Lombard or Petrus Lombardus; 1096, Novara – 21/22 July 1160, Paris), was a scholastic theologian, Bishop of Paris, and author of '' Four Books of Sentences'' which became the standard textbook of ...

in 1376–1377, and received the licentiate and doctorate in theology in 1381. He was affiliated with the university, serving as rector in 1384; among his pupils were

Jean Gerson Jean Charlier de Gerson (13 December 1363 – 12 July 1429) was a French scholar, educator, reformer, and poet, Chancellor of the University of Paris, a guiding light of the conciliar movement and one of the most prominent theologians at the Co ...

and

Nicholas of Clémanges Mathieu-Nicolas Poillevillain de Clémanges (or Clamanges) (born in Champagne (province), Champagne c. 1360, died in Paris between 1434 and 1440) was a French Humanism, humanist and theologian. He studied in the Collège de Navarre, University of ...

. The church's Great Schism, between two popes, arose in 1378. In the spring of 1379, d'Ailly, in anticipation even of the decision of the

University of Paris , image_name = Coat of arms of the University of Paris.svg , image_size = 150px , caption = Coat of Arms , latin_name = Universitas magistrorum et scholarium Parisiensis , motto = ''Hic et ubique terrarum'' (Latin) , mottoeng = Here and a ...

, had carried to the pope of

Avignon Avignon (, ; ; oc, Avinhon, label=Provençal dialect, Provençal or , ; la, Avenio) is the Prefectures in France, prefecture of the Vaucluse Departments of France, department in the Provence-Alpes-Côte d'Azur Regions of France, region of So ...

Clement VII Pope Clement VII ( la, Clemens VII; it, Clemente VII; born Giulio de' Medici; 26 May 1478 – 25 September 1534) was head of the Catholic Church and ruler of the Papal States from 19 November 1523 to his death on 25 September 1534. Deemed "the ...

, the "role" of the French nation. Notwithstanding this prompt adhesion, he was firm in his desire to put an end to the schism, and when, on 20 May 1381, the university decreed that the best means to this end was to gather together a

general council General council may refer to: In education: * General Council (Scottish university), an advisory body to each of the ancient universities of Scotland * General Council of the University of St Andrews, the corporate body of all graduates and senio ...

, d'Ailly supported this motion before the king's council in the presence of the

Duke of Anjou The Count of Anjou was the ruler of the County of Anjou, first granted by Charles the Bald in the 9th century to Robert the Strong. Ingelger and his son, Fulk the Red, were viscounts until Fulk assumed the title of Count of Anjou. The Robertians ...

. The dissatisfaction displayed shortly after by the government obliged the university to give up this scheme, and this was probably the cause of Pierre d'Ailly's temporary retirement to

Noyon Noyon (; pcd, Noéyon; la, Noviomagus Veromanduorum, Noviomagus of the Veromandui, then ) is a Communes of France, commune in the Oise Departments of France, department, northern France. Geography Noyon lies on the river Oise (river), Oise, a ...

, where he held a

canonry A canon (from the Latin , itself derived from the Greek , , "relating to a rule", "regular") is a member of certain bodies in subject to an ecclesiastical rule. Originally, a canon was a cleric living with others in a clergy house or, later, i ...

. There he continued the struggle for his side in a humorous work, in which the partisans of the council are amusingly taken to task by the demon

Leviathan Leviathan (; he, לִוְיָתָן, ) is a sea serpent noted in theology and mythology. It is referenced in several books of the Hebrew Bible, including Psalms, the Book of Job, the Book of Isaiah, the Book of Amos, and, according to some ...

. D'Ailly returned to prominence by leading the university's effort to secure removal of John Blanchard as

chancellor Chancellor ( la, cancellarius) is a title of various official positions in the governments of many nations. The original chancellors were the of Roman courts of justice—ushers, who sat at the or lattice work screens of a basilica or law cou ...

, in which Blanchard was accused by d'Ailly before the Avignon

antipope Clement VII Robert of Geneva, (french: Robert de Genève; 1342 – 16 September 1394) elected to the papacy as Clement VII (french: Clément VII) by the cardinals who opposed Pope Urban VI, was the first antipope residing in Avignon, France. His election l ...

of abuse of office. Subsequently, d'Ailly was twice entrusted with a mission to Clement VII in 1388 to defend the doctrines of the university, and especially those concerning the

Immaculate Conception The Immaculate Conception is the belief that the Virgin Mary was free of original sin from the moment of her conception. It is one of the four Marian dogmas of the Catholic Church, meaning that it is held to be a divinely revealed truth w ...

of the Virgin, against the preaching friar Jean de Montson, and in 1389 to petition in the name of the king for the canonization of the young

Pierre de Luxembourg Pierre de Luxembourg (20 July 1369 – 2 July 1387) was a French Catholic prelate who served as the Bishop of Metz, and as a cardinal of the Avignon Obedience from 1384 until his death. Pierre was descended from nobles who secured his entrance i ...

. The success which attended his efforts on these two occasions, and the eloquence which he displayed, perhaps contributed to his choice as the king's

almoner An almoner (} ' (alms), via the popular Latin '. History Christians have historically been encouraged to donate one-tenth of their income as a tithe to their church and additional offerings as needed for the poor. The first deacons, mentioned ...

and

confessor Confessor is a title used within Christianity in several ways. Confessor of the Faith Its oldest use is to indicate a saint who has suffered persecution and torture for the faith but not to the point of death.chancellor Chancellor ( la, cancellarius) is a title of various official positions in the governments of many nations. The original chancellors were the of Roman courts of justice—ushers, who sat at the or lattice work screens of a basilica or law cou ...

Notre Dame de Paris Notre-Dame de Paris (; meaning "Our Lady of Paris"), referred to simply as Notre-Dame, is a medieval Catholic cathedral on the Île de la Cité (an island in the Seine River), in the 4th arrondissement of Paris. The cathedral, dedicated to the ...

. This acceptability to many interests helps explain his advancement. D'Ailly served as chancellor of the University from 1389 to 1395, and Gerson succeeded him. Both were involved in expelling the

Dominican Order The Order of Preachers ( la, Ordo Praedicatorum) abbreviated OP, also known as the Dominicans, is a Catholic mendicant order of Pontifical Right for men founded in Toulouse, France, by the Spanish priest, saint and mystic Dominic of Cal ...

from the university for refusing to embrace the idea of the Immaculate Conception and in the effort mentioned above to end the Great Schism by means of an ecumenical council. When

Antipope Benedict XIII Pedro Martínez de Luna y Pérez de Gotor (25 November 1328 – 23 May 1423), known as in Spanish and Pope Luna in English, was an Aragonese nobleman who, as Benedict XIII, is considered an antipope (see Western Schism) by the Catholic Church ...

succeeded Clement VII at Avignon in 1394, d'Ailly was entrusted by the king with a mission of congratulation to the new pontiff. His obsequious language on this occasion, and the favours with which it was rewarded, formed a too violent contrast to the determined attitude of the university of Paris, which, tired of the schism, was even then demanding the resignation of the two pontiffs. D'Ailly himself had not long before taken part in the drawing up of a letter to the king in which the advantages of this double abdication were set forth, but since then his zeal had seemed to cool a little. Nevertheless, on his return from Avignon, he again in the presence of the king enlarged upon the advantages offered by the way which the university commended. The suspicions aroused by his conduct found further confirmation when he caused himself—or allowed himself—to be nominated bishop of Le Puy by Benedict on 2 April 1395. The great number of

benefice A benefice () or living is a reward received in exchange for services rendered and as a retainer for future services. The Roman Empire used the Latin term as a benefit to an individual from the Empire for services rendered. Its use was adopted by ...

s which he held left room for some doubt as to his disinterestedness. Henceforward he was under suspicion at the university, and was excluded from the assemblies where the union was discussed.

Ecclesiastical career

Appointments

D'Ailly's ecclesiastical career prospered, however. After Le Puy, he was appointed

Bishop of Noyon The former French Catholic diocese of Noyon lay in the north-east of France, around Noyon. It was formed when Saint Medardus moved the seat of the bishopric at Vermandois to Noyon, in the sixth century. For four centuries it was united with the ...

, and

Bishop of Cambrai The Archdiocese of Cambrai ( la, Archdiocesis Cameracensis; French: ''Archidiocèse de Cambrai'') is a Latin Church ecclesiastical jurisdiction or archdiocese of the Catholic Church in France, comprising the arrondissements of Avesnes-sur-Help ...

(1397). By virtue of this position, he became also a

prince of the Holy Roman Empire Prince of the Holy Roman Empire ( la, princeps imperii, german: Reichsfürst, cf. ''Fürst'') was a title attributed to a hereditary ruler, nobleman or prelate recognised as such by the Holy Roman Emperor. Definition Originally, possessors o ...

. In order to take possession of his new

episcopal see An episcopal see is, in a practical use of the phrase, the area of a bishop's ecclesiastical jurisdiction. Phrases concerning actions occurring within or outside an episcopal see are indicative of the geographical significance of the term, mak ...

, he had to brave the wrath of Philip, Duke of Burgundy, override the resistance of the

clergy Clergy are formal leaders within established religions. Their roles and functions vary in different religious traditions, but usually involve presiding over specific rituals and teaching their religion's doctrines and practices. Some of the ter ...

and

bourgeoisie The bourgeoisie ( , ) is a social class, equivalent to the middle or upper middle class. They are distinguished from, and traditionally contrasted with, the proletariat by their affluence, and their great cultural and financial capital. They ...

, and even withstand an armed attack on the part of several lords; but his protector, the duke of Orleans, had his investiture performed by

Wenceslaus Wenceslaus, Wenceslas, Wenzeslaus and Wenzslaus (and other similar names) are Latinized forms of the Czech name Václav. The other language versions of the name are german: Wenzel, pl, Wacław, Więcesław, Wieńczysław, es, Wenceslao, russian: ...

, king of the Romans. The latter, though a partisan of the pope of Rome, took the opportunity of enjoining on d'Ailly to go in his name and argue with the pope of Avignon, a move which had as its object to persuade Benedict to an abdication, the necessity of which was becoming more and more evident. However, the language of d'Ailly seems on this occasion to have been lacking in decision; however that may be, it led to no felicitous result. From this point on, he spent most of his energy to addressing the schism. Although he was slow at first to embrace the conciliar solution to the Schism, he was participating in councils by 1409.

Schismatic pressures

France next tried to bring violent pressure to bear to conquer the obstinacy of Benedict XIII by threatening a formal withdrawal from his obedience. D'Ailly, who, in spite of his attachment to the pope, had been carried away by the example of the kingdom, was among the first who, in 1403, after experience of what had happened, counselled and celebrated the restoration of obedience. He was sent by Charles VI on an embassy to Benedict and seized this opportunity of lavishing on the pontiff friendly congratulations mingled with useful advice. Two years later, before the same pontiff, he preached in the city of

Genoa Genoa ( ; it, Genova ; lij, Zêna ). is the capital of the Italian region of Liguria and the List of cities in Italy, sixth-largest city in Italy. In 2015, 594,733 people lived within the city's administrative limits. As of the 2011 Italian ce ...

a sermon which led to the general institution, in the countries of the obedience of Avignon, of the festival of the

Holy Trinity The Christian doctrine of the Trinity (, from 'threefold') is the central dogma concerning the nature of God in most Christian churches, which defines one God existing in three coequal, coeternal, consubstantial divine persons: God the F ...

. At the ecclesiastical council which took place at Paris in 1406, d'Ailly made every effort to avert a new withdrawal from the obedience and, by order of the king, took the part of defender of Benedict XIII, a course which yet again exposed him to attacks from the university party. The following year he and his disciple Gerson formed part of the great embassy sent by the princes to the two pontiffs, and while in Italy he was occupied in praiseworthy but vain efforts to induce the pope of Rome to remove himself to a town on the Italian coast, in the neighbourhood of his rival, where it was hoped that the double abdication would take place. Discouraged by his failure to effect this, he returned to his diocese of Cambrai at the beginning of 1408. At this time he was still faithful to Benedict, and the disinclination he felt to joining the members of the French clergy who were on the point of ratifying the royal declaration of neutrality excited the anger of Charles VI's government, and a mandate, which was however not executed, ordered the arrest of the bishop.

Conciliar councils

It was not until after the cardinals of the two colleges had led to the convocation of the

Council of Pisa The Council of Pisa was a controversial ecumenical council of the Catholic Church held in 1409. It attempted to end the Western Schism by deposing Benedict XIII (Avignon) and Gregory XII (Rome) for schism and manifest heresy. The College of C ...

(1409) that d'Ailly renounced his support of Benedict XIII, and, for want of a better policy, again allied himself with the cause which he had championed in his youth. In the council lay now, to judge from his words, the only chance of salvation; and, in view of the requirements of the case, he began to argue that, in case of schism, a council could be convoked by any one of the faithful, and would have the right to judge and even to depose the rival pontiffs. This was, in fact, the procedure of the council of Pisa, in which d'Ailly took part. After the declaration of the deposition of the Roman pope

Gregory XII Pope Gregory XII ( la, Gregorius XII; it, Gregorio XII; – 18 October 1417), born Angelo Corraro, Corario," or Correr, was head of the Catholic Church from 30 November 1406 to 4 July 1415. Reigning during the Western Schism, he was oppose ...

and Benedict XIII, the council went on to elect

Alexander V Alexander is a male given name. The most prominent bearer of the name is Alexander the Great, the king of the Ancient Greek kingdom of Macedonia who created one of the largest empires in ancient history. Variants listed here are Aleksandar, Al ...

(26 June 1409). This pope reigned only ten months; his successor,

John XXIII Pope John XXIII ( la, Ioannes XXIII; it, Giovanni XXIII; born Angelo Giuseppe Roncalli, ; 25 November 18813 June 1963) was head of the Catholic Church and sovereign of the Vatican City State from 28 October 1958 until his death in June 19 ...

, raised d'Ailly to the rank of cardinal (6 June 1411), and further, to indemnify him for the loss of the bishopric of Cambrai, conferred upon him the administration of that of

Limoges Limoges (, , ; oc, Lemòtges, locally ) is a city and Communes of France, commune, and the prefecture of the Haute-Vienne Departments of France, department in west-central France. It was the administrative capital of the former Limousin region ...

(3 November 1412), which was shortly after exchanged for the bishopric of Orange. He also nominated d'Ailly as his

legate Legate may refer to: *Legatus, a higher ranking general officer of the Roman army drawn from among the senatorial class :*Legatus Augusti pro praetore, a provincial governor in the Roman Imperial period *A member of a legation *A representative, ...

in Germany (18 March 1413). Forgetting these benefits, d'Ailly was one of the most formidable adversaries of John XXIII at the

Council of Constance The Council of Constance was a 15th-century ecumenical council recognized by the Catholic Church, held from 1414 to 1418 in the Bishopric of Constance in present-day Germany. The council ended the Western Schism by deposing or accepting the res ...

(1414–1418); with Gerson, d'Ailly was one of the leading theologians at the council. Convinced as he was of the necessity for union and reform, he contributed more than anyone to the adoption of the principle that, since the schism had survived the

, it was necessary again to take up the work for a fundamental union, without considering the rights of John XXIII any more than they had those of Gregory XII and Benedict XIII. From this point of view d'Ailly, together with his compatriot Cardinal Fillastre, took the preponderating part during the first few months. Afterwards, seeing the trend of events, he showed some uneasiness and hesitation. He refused, however, to undertake the defence of John XXIII, and only appeared in the trial of this pope to make depositions against him, which were sometimes of an overwhelming character. Other matters which claimed his attention at Constance included the condemnation of

John Wycliffe John Wycliffe (; also spelled Wyclif, Wickliffe, and other variants; 1328 – 31 December 1384) was an English scholastic philosopher, theologian, biblical translator, reformer, Catholic priest, and a seminary professor at the University of O ...

and the trial of

Jan Hus Jan Hus (; ; 1370 – 6 July 1415), sometimes anglicized as John Hus or John Huss, and referred to in historical texts as ''Iohannes Hus'' or ''Johannes Huss'', was a Czech theologian and philosopher who became a Church reformer and the inspir ...

. The reading in public of his two treatises ''De Potestate ecclesiastica'' and ''De Reformatione Ecclesiae'' revealed, besides ideas very peculiar to himself on the reform and constitution of the church, his design of reducing the power of the

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

in the council by denying them the right of forming a separate nation (1 October1 November 1416). By this campaign, which exposed him to the worst retaliation of the English, he inaugurated his role of "procurator and defender of the king of France." When at last the question arose of giving the Christian world a new pope, this time sole and uncontested, d'Ailly defended the right of the cardinals, if not to keep the election entirely in their own hands, at any rate to share in the election, and he brought forward a system for reconciling the pretensions of the council with the rights of the

College of Cardinals The College of Cardinals, or more formally the Sacred College of Cardinals, is the body of all cardinals of the Catholic Church. its current membership is , of whom are eligible to vote in a conclave to elect a new pope. Cardinals are appoi ...

. In this way was elected

Pope Martin V Pope Martin V ( la, Martinus V; it, Martino V; January/February 1369 – 20 February 1431), born Otto (or Oddone) Colonna, was the head of the Catholic Church and ruler of the Papal States from 11 November 1417 to his death in February 1431. Hi ...

(11 November 1417), and the task of d'Ailly was at last finished.

Retirement

After the council, d'Ailly returned to Paris. When in France's civil discord the Burgundian faction seized Paris in 1419, killing some professors in the process, he fled south and retired to

. His former pupil Gerson settled nearby at a house of the

Celestine Order The Celestines were a Roman Catholic monastic order, a branch of the Benedictines, founded in 1244. At the foundation of the new rule, they were called Hermits of St Damiano, or Moronites (or Murronites), and did not assume the appellation of C ...

. D'Ailly, known as the Cardinal of Cambrai, died in 1420 in Avignon.

Writings

D'Ailly wrote extensively on the Schism, reform, astrology and other topics. His ideas on the powers of the

college of cardinals The College of Cardinals, or more formally the Sacred College of Cardinals, is the body of all cardinals of the Catholic Church. its current membership is , of whom are eligible to vote in a conclave to elect a new pope. Cardinals are appoi ...

and the

infallibility Infallibility refers to an inability to be wrong. It can be applied within a specific domain, or it can be used as a more general adjective. The term has significance in both epistemology and theology, and its meaning and significance in both fi ...

of the general council were very influential. D'Ailly's ''Imago Mundi'' (1410), a work of

cosmography The term cosmography has two distinct meanings: traditionally it has been the protoscience of mapping the general features of the cosmos, heaven and Earth; more recently, it has been used to describe the ongoing effort to determine the large-sca ...

, influenced

Christopher Columbus Christopher Columbus * lij, Cristoffa C(or)ombo * es, link=no, Cristóbal Colón * pt, Cristóvão Colombo * ca, Cristòfor (or ) * la, Christophorus Columbus. (; born between 25 August and 31 October 1451, died 20 May 1506) was a ...

in his estimates of the size of the world. Many questions in science and astrology, such as

calendar reform Calendar reform or calendrical reform is any significant revision of a calendar system. The term sometimes is used instead for a proposal to switch to a different calendar design. Principles The prime objective of a calendar is to unambigu ...

, attracted his attention. His views on astrology, expressed in several works, attempted to balance divine omniscience and human

free will Free will is the capacity of agents to choose between different possible courses of action unimpeded. Free will is closely linked to the concepts of moral responsibility, praise, culpability, sin, and other judgements which apply only to actio ...

. D'Ailly's writings on the Schism put the crisis and the need for reform into an apocalyptic context. His astrology also was tied to the Schism, attempting to determine whether the division of the church was a sign of the coming of the

Antichrist In Christian eschatology, the Antichrist refers to people prophesied by the Bible to oppose Jesus Christ and substitute themselves in Christ's place before the Second Coming. The term Antichrist (including one plural form) 1 John ; . 2 John . ...

. His works began appearing in print before the end of the fifteenth century.

Legacy

In ''

The Eighteenth Brumaire of Louis Napoleon ''The Eighteenth Brumaire of Louis Napoleon'' (german: italic=yes, Der 18te Brumaire des Louis Napoleon) is an essay written by Karl Marx between December 1851 and March 1852, and originally published in 1852 in ''Die Revolution'', a German mo ...

'',

Karl Marx Karl Heinrich Marx (; 5 May 1818 – 14 March 1883) was a German philosopher, economist, historian, sociologist, political theorist, journalist, critic of political economy, and socialist revolutionary. His best-known titles are the 1848 ...

wrote that d'Ailly had told advocates of ethical reform at the Council of Constance, "Only the devil in person can still save the Catholic Church, and you ask for angels."K. Marx (1869), ''The Eighteenth Brumaire of Louis Bonaparte'', 1934 translation, Moscow: Progress Publishers, Chapter VII, p. 112. The crater Aliacensis on the Moon is named after him.

Works and translations

* ''Quaestiones super libros Sententiarum'' (1376–1377), anastatic reprint of the edition of 1490: Frankfurt-am-Mein: Minerva, 1968. * ''Petrus de Alliaco Questiones super primum, tertium et quartum librum Sententiarum. I: Principia et questio circa Prologum'', cura et studio Monica Brinzei, Turnhout: Brepols, 2013. * ''Ymago Mundi de Pierre d'Ailly'', Edmond Burton (ed.), Paris: Maisonneuve Frères, 1930, 3 vols., vol. 1 online
here
'. * ''De concordia astronomice veritatis et narrationis historice'' (1414). * ''Tractatus de concordantia theologie et astronomie'' (1414). * ''Destructiones modorum significandi'', L. Kaczmarek (ed.), Amsterdam: G. B. Grüner, 1994. * ''Tractatus de anima'', O. Pluta (ed.), in ''Die philosophische Psychologie des Peter von Ailly'', Amsterdam: G. B. Grüner, 1987. * ''Tractatus super De consolatione philosophiae'', M. Chappuis (ed.), Amsterdam: G. B. Grüner, 1988. * ''Conceptus et insolubilia'' Paris, . * ''Concepts and Insolubles: An Annotated Translation'', Paul Vincent Spade (ed.), Dordrecht: Reidel, 1980. * ''Destructions modorum significandi. Conceptus et insolubilia'', Lyons . * ''Tractatus exponibilium'', Paris 1494.

Manuscripts

* 18th century AD

References

* Alan E. Bernstein, ''Pierre d'Ailly and the Blanchard affair: University and Chancellor of Paris at the Beginning of the Great Schism'', Leiden: Brill, 1978. * Bernard Guenée, ''Between Church and State: The Lives of Four French Prelates in the Late Middle Ages'', Translated by

Arthur Goldhammer Arthur Goldhammer (born November 17, 1946) is an American academic and translator. Early life Goldhammer studied mathematics at MIT, gaining his PhD in 1973. Career Since 1977 he has worked as a translator. He is based at the Center for Europ ...

, Chicago: University of Chicago Press, 1991. * Louis B. Pascoe, ''Church and Reform: Bishops, Theologians, and Canon Lawyers in the Thought of Pierre d'Ailly (1351–1420)'', Leiden: Brill, 2005. * Laura Ackerman Smoller, ''History, Prophecy, and the Stars – The Christian Astrology of Pierre d'Ailly, 1350–1420'', Princeton, NJ: Princeton University Press, 1994. . * Philip H. Stump, ''The Reforms of the Council of Constance (1414–1418)'', Leiden: Brill, 1994. . * Bibliography cited: ** P. Tschackert, ''Peter van Ailli'' (Gotha, 1877) ** L. Salembier, ''Petrus de Alliaco'' (Lille, 1886) ** H. Denifle and Em. Chatelain, ''Chartularium Universitatis Parisiensis'', t. iii. (Paris, 1894) ** N. Valois, ''La France et le Grand Schisme d'Occident'' (Paris, 4 vols., 1896–1902) ** ''Bibliothèque de l'école des chartes'', vol. lxv., 1904, pp. 557–574.