Abstract
Taking its cue from the famous articles in which the Jesuit Marcel Chossat, in the early decades of the last century, was the first to suggest that the doctrine of the real distinction between being and essence should be attributed to Giles of Rome, and not to Thomas Aquinas, the article proposes to consider the Neoplatonic matrix of Giles’ distinction, and to re-examine in more detail the doctrine of participation, which is the real trigger of the controversy between Giles and Henry of Ghent. It suggests that Thomas Aquinas, Henry and Giles all three draw on the Proclean tradition, but each choosing different elements, as attested especially by the different readings of the fourth and ninth proposition of the De causis. Finally, it points out that the purpose of the distinction between being and essence is not at all, in Aquinas, to account for the contingency of creation, but to highlight the superiority of God not only with respect to all that possesses matter, but also to all that possesses only a form, even if intrinsically necessary. The distance between Giles and Aquinas could not be greater in this respect: the Dominican Master is not at all interested in showing the radical contingency of all creatures, including separate substances. On the contrary, insofar as he defends the idea that separate substances, as pure forms, are inseparable from their being, it remains true that one could legitimately speak, with regard to this aspect, of “St Thomas’ Averroism”, as Chossat wanted.