Thinking the Divine Tri--Unity. Some Reflections on the Trinitarian Ontology of James of Viterbo based on the edition of questions 28--32 in De Divinis Praedica--mentis.

One of the most interesting but to date least studied aspects of James of Viterbo’s thought is undoubtedly his Trinitarian ontology, which he dealt with on several occasions during his teaching as magister at the Augustinian studium generale in Paris. Drawing on the edition of questions 28--32 of James’s De divinis praedicamentis, the article aims to evaluate the originality of his contribution to the late medieval debate on unity and distinction in God. Based on a close comparison with the opinions of some magistri moderni (especially Thomas Aquinas, Bonaventure of Bagnoregio, Henry of Ghent, Giles of Rome), but also thanks to a rigorous grounding in the philosophicotheological traditions of Augustine and Boethius, James reached a synthesis solution, in which the relation and the emanation accounts (focused respectively on relations and on emanations as the factor making the divine persons distinct) coexist within a “strong” use of the psychological model, whose ultimate foundation lies in the universal properties of being. The different arrangement of the material in the manuscript tradition confirms the “dual nature” (ontological and psychological) of James’s Trinitarian teaching.

Keywords: Augustinian, psychology, categories, emanation, ontology, relation, Trinity.

Gianpiero Tavolaro, Pensare la tri-unità divina. Alcune considerazioni sull’ontologia trinitaria di Giacomo da Viterbo a partire dall’edizione delle questioni 28-­32 De divinis praedicamentis in "RIVISTA DI STORIA DELLA FILOSOFIA" 2/2026, pp 207-232, DOI: 10.3280/SF2026-002001