ABSTRACT
Furthermore, “priority” is not the only problematic issue at stake, as the very notion of “being” in ancient philosophy is contentious. It is controversial whether we should identify Plato’s ousia with what exists primarily (this would involve the controversial notion of degrees of existence) or rather with what is F in a primary (i.e. stable and invariant) sense. A possible way out from this di culty would be that of regarding the very distinction between “to exist” and “to be F” (something like the later scholastic distinction between existence and essence) as inadequate for grasping how ancient philosophers, and Plato in particular, conceived of “being”: for the ancient way of understanding “being” entails that “existence” is always “being something” and that there is no concept of existence as such
for subjects of indeterminate nature.2 When we come to Aristotle, the issue becomes even more puzzling because di erent accounts of ousia co-exist in his corpus. In the Categories, Aristotle presents the particular subjects of properties (e.g. the individual human being, the individual horse) as primary ousiai. Furthermore, he does not mention the distinction between form and matter and conceives of universal species and genera (e.g. human being, animal) as secondary ousiai (Cat. 5.2a11-19). In the Metaphysics, instead, form is regarded as primary ousia within a hylomorphic account of physical realities. Unlike what happens in the Categories, substancehood and subjecthood are no longer straightforwardly equated in the Metaphysics (Metaph.1029a7-b30). In the Metaphysics form is that which makes a composite substance what it is. Hence form can be seen as primary substance (Metaph.1037a28-30), even if it is in matter and cannot exist apart from it. In turn, the Stoics identi ed ousia with the passive cosmic material and unquali ed principle (Diogenes Laertius 7.134 [SVF I.85] and 150 [SVF I.87]). is was probably a polemical move against Plato and Aristotle’s previous identi cation of ousia with form: the very concept of eidos has no place in Stoic corporealist ontology.
