Giles of Rome

Giles of Rome, known in Latin as Aegidius Romanus, was born in Rome around 1243 ^[1]. Later tradition attached him to the powerful Colonna family, which is why some older sources call him Egidio Colonna, but modern scholars regard that family connection as unproven and probably a later invention ^[2]. Whatever his parentage, his birthplace gave him the name by which the medieval schools knew him.

As a boy he entered the Order of the Hermits of Saint Augustine, a mendicant order that had been formally organized only in 1256, shortly before or around the time he joined ^[1]. The Augustinians, eager to build an intellectual reputation to match the Dominicans and Franciscans, sent their most promising recruits to Paris. Giles arrived at the University of Paris around 1260 and spent the following years working through the arts curriculum and then theology, the standard long apprenticeship of a medieval schoolman ^[3].

Paris in those decades was the most contested intellectual arena in Latin Christendom. The recently translated works of Aristotle, along with commentaries by Muslim philosophers such as Averroes, were forcing theologians to decide how far pagan philosophy could be reconciled with Christian doctrine. It was into this argument that the young Roman friar was thrown, and it defined the rest of his career ^[3].

In Paris Giles studied under Thomas Aquinas, probably between 1269 and 1272, during the Dominican master's second Parisian regency ^[1]. The connection marked him deeply. Giles absorbed much of Aquinas's method and many of his positions, though he was never a slavish follower and disagreed with his teacher on significant points, including the relationship between essence and existence, a question on which Giles developed his own distinctive account ^[4].

His independence brought trouble. In 1277 the bishop of Paris, Stephen Tempier, issued a sweeping condemnation of 219 philosophical propositions circulating in the university. In the same climate of suspicion, a list of theses drawn from Giles's own writings was censured, and when he refused to retract them he was denied the license to teach as a master of theology ^[2]. He left Paris and spent several years away from the classroom, a serious setback for a scholar of his ambitions.

Rehabilitation came from the top. In 1285 Pope Honorius IV intervened, and after a qualified retraction Giles was permitted to return and take up his chair ^[2]. He thereby became the first member of the Augustinian order to serve as a regent master of theology at Paris, a milestone the order celebrated ^[1]. Two years later, in 1287, the Augustinian general chapter meeting at Florence took the extraordinary step of directing that the order's schools should teach the opinions of Giles, both those he had written and those he would write in the future, effectively making a living man the official doctor of his order ^[3].

Anyone asking who was Giles of Rome usually meets him first through a single book. Around 1277 to 1279 he composed De regimine principum (On the Government of Princes) for the young Philip, heir to the French throne, whom he served as tutor ^[5]. The treatise, built on Aristotle's ethics and politics, explained how a prince should govern himself, his household, and his kingdom. It became one of the genuine bestsellers of the later Middle Ages: hundreds of Latin manuscripts survive, and it was translated into French, Italian, Castilian, Portuguese, English, and other vernaculars, carrying Aristotelian political ideas to courts across Europe ^[5].

His later political writing pulled in a different direction. During the bitter quarrel between Pope Boniface VIII and his former pupil, now King Philip IV of France, Giles wrote De ecclesiastica potestate (On Ecclesiastical Power) in 1301 to 1302, arguing that the pope holds supreme authority over both spiritual and temporal affairs and that legitimate lordship over property ultimately depends on the Church ^[6]. The work supplied much of the theoretical scaffolding for Boniface's famous bull Unam Sanctam of 1302, one of the strongest assertions of papal supremacy ever issued ^[6]. That the same author produced the era's most read mirror for princes and its most uncompromising defense of papal power is one of the striking Giles of Rome facts.

Beyond politics, his output was enormous. He wrote commentaries on Aristotle's logic, physics, and On the Soul, commentaries on the Sentences of Peter Lombard, quodlibetal questions, scriptural commentaries, and treatises on angels, original sin, and the formation of the human body in the womb ^[4]. His Theoremata de esse et essentia set out his theory that essence and existence are distinct as two "things" (res), a stronger claim than Aquinas had made and one that later scholastics debated for centuries ^[4]. An early work, De erroribus philosophorum, catalogued the errors of Aristotle, Averroes, Avicenna, and other philosophers, and circulated widely as a handbook of what Christian readers should treat with caution ^[3].

As a mendicant friar Giles took vows of poverty, chastity, and obedience, so he left no family and little private documentation; his personality must be read from his career and his prose ^[1]. Contemporaries and later admirers called him Doctor Fundatissimus, the "best grounded teacher", a title that reflected his reputation for thoroughness and system rather than for rhetorical flash ^[2].

His defining personal relationships were institutional. To his order he was patron and standard-bearer: he served as prior general of the Augustinian Hermits from 1292 until his promotion to the episcopate in 1295, guiding the young order's studies and organization ^[1]. To the French court he was the learned tutor whose royal student outgrew him, and the later rupture between Philip IV and the papacy placed Giles firmly on the pope's side against the king he had once instructed ^[6].

He was also capable of hard partisanship. When Pope Celestine V resigned in 1294 and Boniface VIII succeeded him, critics questioned whether a pope could validly abdicate. Giles wrote in defense of the renunciation, supporting Boniface's legitimacy at a moment when the question was politically explosive ^[2].

In 1295 Boniface VIII appointed Giles archbishop of Bourges, one of the senior sees of France ^[1]. The appointment was contested at first, since another candidate had claims on the see, but Giles prevailed and held the archbishopric for the rest of his life. As archbishop he remained a busy participant in the great ecclesiastical controversies of the day rather than retiring into diocesan routine ^[2].

The last decade of his life unfolded in the shadow of the papacy's move toward Avignon. Giles attended the Council of Vienne (1311 to 1312), where the fate of the Knights Templar was decided, and he took part in the theological disputes of the council, including the examination of the views of the Franciscan Peter John Olivi ^[2]. His stance in these years remained what it had long been: a defense of firm hierarchical authority in the Church.

Giles died at Avignon on December 22, 1316, where the papal court then resided ^[1]. His body was returned to Paris and buried in the church of the Augustinian convent, the house of the order he had led and made famous ^[3].

The measure of the Giles of Rome achievements is the sheer duration of his influence. De regimine principum remained required reading for princes and their tutors well into the Renaissance, and its manuscript tradition is among the largest of any medieval secular text ^[5]. Within his own order, the 1287 decree made his teaching the official doctrine of Augustinian schools, so generations of friars were trained on his works, and later Augustinian thinkers down to the eve of the Reformation cited him as their doctor ^[3].

Historians of political thought treat him as an essential figure on both sides of the medieval argument about power. His mirror for princes helped naturalize Aristotelian ideas of kingship in European courts, while De ecclesiastica potestate became the classic statement of extreme papal hierocracy, the position against which writers such as John of Paris and later Marsilius of Padua reacted ^[6]. Any serious Giles of Rome biography therefore has to hold together a thinker who armed both monarchy and papacy with arguments.

In philosophy his star faded after the Middle Ages, but modern scholarship has revived interest in him. Critical editions of his works have been appearing since the twentieth century under the series Aegidii Romani Opera Omnia, and his positions on essence and existence, cognition, and embryology are studied as important independent developments within, and sometimes against, the Thomist tradition ^[4]. Seven centuries after his death in Avignon, the Roman friar remains a fixture of every survey of medieval thought ^[1].