Enneads VI.3: Plotino's Own Sense-Categories
Conclusion of the Study
28. We have demonstrated that acting and experiencing were movements; that, among the movements, some are absolute, while others constitute actions or passions.
We have also demonstrated that the other things that are called genera must be reduced to the genera we have set forth.
We have also studied relation, defining it as a habit, a “manner of being” of one thing in respect of another, which results from the co-operation of two things; we have explained that, when a habit of being constitutes a reference, this thing is something relative, not so much as it is being, but as far as it is a part of this being, as are the hand, the head, the cause, the principle, or the element. The relatives might be divided according to the scheme of the ancient (philosophers), by saying that some of them are efficient causes, while others are measures, that the former distinguish themselves by their resemblances and differences, while the latter consist in excess or in lack.
Such are our views about the (categories, or) genera (of existence).