Substances and relatives in Aristotle's categories (chapter 7)

The chapter on relatives in Categories (chap. 7) can easily be divided into three sections. The first gives an initial definition of relatives (6a36-37), the second deals with the properties fo relatives (6b15-8a12), and the third raises an aporia prompting Aristotle to propose a new definition of relatives, which apparently provides an answer (8a13-b21). The chapter's structure is quite clear, yet each section contains a problem that seems to undermine its consistency. In this article the Author presents Aristotle's two definitions of relatives, focusing on the aporia that takes him from the first to the second. To what extent the second definition can be seen to solve the aporia is also examined.