Keywords: Metaphysics; Theory of Distinction; Formal Distinction; Modal Distinction; Principle of Individuation; the One and the Many Problem; John Duns Sco- tus; Scholasticism.
In order to correctly understand the main metaphysics doctrines supported by John Duns Scotus (1265-1308), namely the univocity of being and the principle of individuation, we need to analyze his doctrine of distinction. This paper offers a critical exam of the main types of distinction introduced by Scotus, mainly with regard to the individuation problem. Although the overwhelming majority of scholars claims that there is a formal distinction between natura communis and differentia ultima, this article intends to show that the modal distinction is more suitable to preserve individual unity. Moreover, we will point out that human intellect pro statu isto is not able to distinguish between modal and rational distinction, albeit it can demonstrate they are not the same