Common Natures and Metaphysics in John Duns Scotus

The paper argues that Scotus’s contentions about the ontological status of common natures have a bearing both on his own understanding of the nature of metaphysics and on contemporary discussions about the actual import of metaphysical speculation. An historical reconstruction of an author’s thought cannot be separated from its comprehension in a theoretical dimension. Scotus derives his notion of common natures from Avicenna and conceives of them as devoid of factual existence. Common natures are expressed by definitonal or quidditative discourse, a higher-order form of predication and discourse, and there is a strict correspondence between the semantic doctrine of quidditative discourse and the ontological doctrine of common natures. The interconnection between logic and ontology is particularly obvious in Scotus’s doctrine of the formal distinction, which in turn implies the assumption of the principle of the identity of indiscernibles. And it is only through the admission of that principle that two opposing views of contemporary nominalism, the one which countenances only concrete, as opposed to abstract entities, and the other which countenances only individual, as opposed to universal entities, can be reconciled. The principle of the identity of the indiscernibles implies the equivalence of the two polarities and the doctrine of the formal distinction, that presupposes its validity, brings them back to a unique and indistinct foundation, that is prior to their coming to be. The indifference of common natures to both oppositions acknowledges the ambivalence and paradoxical character of the primary condition of Being, as expressed in contemporary terms by Merleau-Ponty’s conception of the "chiasm", or intertwining. The doctrine of common natures is also functional to Scotus’s theology and witnesses its striking closeness to the most daring endeavours of contemporary metaphysical speculation.