Giles of Rome

Life and Historical Context

Giles of Rome (Aegidius Romanus, c.1243–1316) was an Italian Augustinian friar, scholastic philosopher, and churchman active in the second half of the thirteenth century and the early fourteenth. Born in Rome into the Colonna milieu, he entered the Order of Hermits of Saint Augustine around 1256. He went to Paris to study, probably in the early 1260s, at a time when the Latin West was rapidly absorbing the newly translated corpus of Aristotle together with its Arabic and Jewish commentators.

At Paris, Giles studied under Thomas Aquinas, and his earliest writings show a strong Thomistic influence. By the mid‑1270s he had become one of the leading masters of theology at the University of Paris, lecturing on the Sentences of Peter Lombard and on Aristotle’s works in logic, natural philosophy, and metaphysics. His prominence, however, also exposed him to controversy.

In 1277 Bishop Étienne Tempier of Paris famously condemned a series of philosophical and theological theses as incompatible with Christian doctrine. Some positions either held or associated with Giles were implicated, leading to his temporary suspension from teaching. Although modern scholars debate the extent of his involvement, this episode illustrates the tense climate surrounding the reception of Aristotelian philosophy. After revising some of his views, he was restored to favor and went on to serve as prior general of the Augustinian Order (1285–1292).

Giles also became closely connected to the papal court. He served as tutor to Philip IV (“the Fair”) of France and later, under Pope Boniface VIII, was appointed archbishop of Bourges in 1295. His later years were spent largely in ecclesiastical administration and in the papal orbit (eventually at Avignon), though he continued to write. He died in Avignon on 22 December 1316.

Philosophical and Theological Work

Giles’s corpus spans metaphysics, psychology, ethics, theology, and scriptural exegesis, and includes extensive commentaries on Aristotle. His major systematic work is the Theoremata de esse et essentia and, above all, the vast Theoremata de ente et essentia and the theological synthesis often referred to as the Theoremata theologica (titles vary in the manuscript tradition). He also composed an influential Commentary on the Sentences and treatises on the human soul and knowledge.

A central feature of his metaphysics is a strong realism about forms and universals combined with a hierarchical, creation‑centered ontology. Building on Aristotelian categories but read through an Augustinian lens, Giles developed a view in which God’s being and causality ground all created reality. He defended the real distinction between essence and existence in creatures, a theme that he elaborated more sharply than many contemporaries. While influenced by Aquinas, he articulated his own positions on issues such as the composition of substances, the nature of individuation, and the structure of accidents.

In philosophical psychology, Giles argued for the unity of the soul as the single substantial form of the human being, emphasizing intellectual and volitional capacities as ordered to God. His account of cognition follows Aristotelian lines (sensible species, phantasms, and the agent intellect) but is framed within an Augustinian understanding of illumination and divine concurrence. Discussions of free will, grace, and merit in his theological works contributed to later scholastic debates, especially within the Augustinian tradition.

Theologically, Giles sought a systematic integration of Aristotelian philosophy with Christian doctrine, yet with greater insistence than Aquinas on divine transcendence and the primacy of will. He helped shape what some scholars call an “Augustinian Thomism”: the adoption of many Thomistic analytical tools and distinctions, combined with a stronger emphasis on God’s absolute power and on the dependence of created order on divine volition.

Political Thought and Legacy

Giles is especially notable in the history of medieval political philosophy for his treatise De ecclesiastica potestate (On the Power of the Church), written around the time of his elevation to the archbishopric of Bourges. Composed in the context of mounting tensions between Boniface VIII and secular rulers—particularly the French monarchy—this work presents one of the most sophisticated statements of late medieval papalism.

In De ecclesiastica potestate, Giles argues that all legitimate temporal power ultimately derives from spiritual authority, embodied pre‑eminently in the pope. Drawing on Aristotelian notions of the hierarchy of ends, he maintains that because the ultimate end of human life is supernatural beatitude, the spiritual power ordered to that end is superior to temporal power, which concerns merely civil peace and material well‑being. From this hierarchical ordering of ends he infers a hierarchy of jurisdictions, in which the pope may, under certain conditions, intervene in and even depose secular rulers for the spiritual welfare of the faithful.

Proponents have viewed Giles’s theory as a rigorous attempt to systematize the Church–state relationship within an overarching metaphysical and teleological framework, giving philosophical depth to earlier papal claims. Critics, both medieval and modern, have regarded it as an extreme form of theocratic centralization, reading it as a justification of papal interventionism into the political sphere. In the early fourteenth century, his positions were challenged by thinkers such as John of Paris and, more broadly, by monarchomachs and conciliarists who defended more autonomous temporal authority or limitations on papal power.

Giles’s political work influenced the drafting and defense of the papal bull Unam sanctam (1302), often considered the high‑water mark of medieval papal plenitude of power. His writings were cited in curial circles and circulated widely, especially among canonists and theologians engaged in debates over sovereignty.

Beyond politics, Giles’s Aristotelian commentaries and theological treatises shaped the intellectual life of the Augustinian Order and beyond. He was sometimes called Doctor Fundatissimus (“the most solidly grounded doctor”), reflecting his perceived role in consolidating a distinctively Augustinian voice within scholasticism. Later medieval authors, including Gregory of Rimini and other Augustinians, engaged extensively with his views, either adopting or refining his positions on grace, predestination, and knowledge.

In modern scholarship, Giles of Rome is studied as a key figure in three overlapping histories: the reception of Aristotle in the Latin West, the internal development of scholastic metaphysics and theology, and the articulation of papalist political theory. While he is less widely known than Aquinas or Bonaventure, his works illustrate how late‑thirteenth‑century thinkers negotiated the balance between philosophical reasoning and ecclesiastical authority, and how metaphysical and theological commitments could shape concrete views on law, sovereignty, and the structure of Christian society.