ABSTRACT
Any interpretation of the Categories is a daunting enterprise, since almost everything is controversial about it: its unity, its theses, its authenticity, and even its title are matters of debate. This chapter comes to grip with these issues and endeavours to show, based on a fine-grained analysis of the formal structure of Chapters 5 to 8, which is surprisingly pretty similar, that there is a plan underpinning the whole treatise. Once this plan is brought to light, one can see that the Categories provide us with an ontology without hylomorphism by dividing all there is into ten classes through the way the several items that exist satisfy two common-traits (contrariety and the presence of degrees) and by distributing them in accordance with proper traits that belong only to the members of a given category and to all of them. Comments are also made on the interpretation the Greek commentators offered of this treatise, especially as regards the common-traits and proper characteristic traits, the interpretation of which is crucial for an interpretation of the structural unity of the entire treatise.
