I propose to consider the Plotinian reduction of Aristotle’s categories, especially as presented in the problematic VI. 3. 3. The following questions will be discussed: Which of the Aristotelian categories did Plotinus consider dispensable and for what specific reasons? Are there any non-Aristotelian categories in the Plotinian set and, if so, where do they come from and how do they function? By what method, if any, did Plotinus determine the number of his set of categories and why just five? Finally, why is it that Plotinus is the last, in a long series of Platonists, to sharply criticize Aristotle’s doctrine of categories? For it is known that his followers and admirers became increasingly interested in (and commented favorably on) Aristotle's categories.
Evangeliou, Christos C., "The Plotinian Reduction of Aristotle's Categories" (1987). The Society for Ancient Greek Philosophy Newsletter. 185.