Simplicius on the Individuation of Material Substances

Abstract

Abstract In his commentary on Physics I 9, Simplicius claims that individual forms individuate matter. Given that in the same text he calls the immanent form ‘universal,’ it seems reasonable to conclude that the individual forms are individual instances of one universal species–form. However, Simplicius also mentions accidental properties that are peculiar to form rather than to matter. On the basis of Simplicius’ commentaries on the Categories and on the Physics, I argue that the individuating accidents are not part of the individual forms, but that each individual’s form coordinates the individual’s accidental features. By belonging to a certain species, the individual form sets limits as to which accidents a matter–form compound can assume. This approach enables Simplicius to combine hylomorphism with a theory of individuation through properties. Furthermore, in his commentary on De Caelo I 9 Simplicius explains the uniqueness of each individual’s conglomeration of properties in light of his Neoplatonic cosmology: each individual corresponds to an individual cosmic disposition that determines its characteristic features.