“Tre e uno”: A trinitarian formula in Dante’s Commedia Jia Aijia and Thomas Rendall Abstract Studies of Dante’s numerology have focused on the obvious significance of such single numbers as 3, 9, and 10, or have proposed schemes of bewildering complexity. However, a neglected aspect of Dante’s obsession with numbers is his juxtapositions of 3 and 1, as well as with factorizations of 3 plus 1. Patterns of “tre e uno” that fully embody the Christian concept of the Godhead are found in the Commedia’s words, lines of verse, cantos, canticles, and overall structure. Keywords Dante, divine comedy, numerology, trinity A major focus of Dante’s writing, from the beginning to the end of his career, was the Trinity. Although Dante’s use of 3 as a number representing divinity is universally recog- nized, that number alone does not adequately define the orthodox medieval conception of the nature of God. In fact, emphasis on the three persons of God without simultaneous assertion of his unity was a persistent Christian heresy. 1 As will be shown in this note, Dante took pains to make certain his numerological allusions to the Christian Godhead embodied the comprehensive formula of the Trinity, “tre e uno.” 2 In Dante’s early Vita Nuova, he explains that his beloved lady, Beatrice, is a “mira- colo” because of her repeated association with the number 9, the square of 3, “cioè Padre e Figlio e Spirito Santo, li quali sono tre e uno” (“that is Father and Son and Holy Spirit, which are three and one,” 29.3). This assertion is also mirrored in the work’s Peking University, Beijing, China Corresponding author: Thomas Rendall, Department of English, Peking University, Beijing 100871, China. Email: beijingrendalls@yahoo.ca Original research article Forum Italicum 1–6 © The Author(s) 2025 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/00145858251353740 journals.sagepub.com/home/foi